perf(P6C.T12): optimistic UI for mute / mentions-only / archive / pin / device-revoke

Audit of write-actions revealed that send (and edit via realtime UPDATE) are
already optimistic via local state insertion in `useConversationMessages`,
and friend nicknames are pure-local localStorage. Five user-write actions
were waiting on the ~100-200 ms server roundtrip + realtime echo:

* Toggle mute (`setConversationMutedUntil`)
* Toggle mentions-only (`setConversationMentionsOnly`)
* Toggle archive (`setConversationArchived`)
* Pin / unpin message (`pinMessage` / `unpinMessage`)
* Revoke device (`revokeDevice` RPC)

All five now flip local state synchronously and roll back on failure. The
existing realtime subscriptions reconcile canonically (no-op when the
optimistic patch already matches the server row), so this is purely a UX
latency improvement — no protocol or persistence changes.

Reactions (`toggleReaction` / `voteExclusive`) were intentionally skipped
this round: rollback semantics for the exclusive-vote path with multiple
sequential awaits are messy enough to warrant a dedicated pass.

.gitignore

@@ -33,6 +33,10 @@ web-build/
 apps/desktop/out/
 apps/desktop/release/
 
+# Bundle visualizer reports
+apps/desktop/stats.html
+apps/desktop/stats.json
+
 # Logs
 *.log
 npm-debug.log*

apps/desktop/electron.vite.config.ts

@@ -10,6 +10,9 @@
 import react from '@vitejs/plugin-react';
 import { defineConfig, externalizeDepsPlugin } from 'electron-vite';
 import path from 'node:path';
+import { visualizer } from 'rollup-plugin-visualizer';
+
+const ANALYZE = process.env.ANALYZE === 'true';
 
 const rendererAliases = {
   '@': path.resolve(__dirname, './src'),
@@ -44,7 +47,30 @@ export default defineConfig({
     // bundle. Relative base produces `./assets/...` which works in both
     // dev (served from /) and packaged builds.
     base: './',
-    plugins: [react()],
+    // Visualizer plugins are gated behind ANALYZE=true so the production
+    // build never pays the analysis cost. Re-enable with:
+    //   ANALYZE=true pnpm --filter @chat-app/desktop build
+    // which writes apps/desktop/stats.html (treemap) + stats.json (raw).
+    plugins: [
+      react(),
+      ...(ANALYZE
+        ? [
+            visualizer({
+              filename: 'stats.html',
+              template: 'treemap',
+              gzipSize: true,
+              brotliSize: true,
+              open: false,
+            }),
+            visualizer({
+              filename: 'stats.json',
+              template: 'raw-data',
+              gzipSize: true,
+              brotliSize: true,
+            }),
+          ]
+        : []),
+    ],
     resolve: {
       alias: rendererAliases,
     },

apps/desktop/electron/ipc-types.ts

@@ -106,6 +106,19 @@ export const CHANNELS = {
   // Used by the call cinema mode to flip the host BrowserWindow into real
   // OS fullscreen so the Windows taskbar / macOS menubar gets covered.
   WINDOW_SET_FULLSCREEN: 'window:set-fullscreen',
+
+  // Wipe-on-close — main process pushes this to the renderer right before
+  // exiting if the user has enabled the Settings → Sicherheit toggle. The
+  // renderer clears its sensitive caches (memoryWipe.ts) and acks via
+  // `app:wipe-before-quit:done`; main quits after the ack (or a 2s safety
+  // timeout, whichever comes first).
+  /** Main → renderer: about to quit. Renderer wipes, then resolves. */
+  APP_WIPE_BEFORE_QUIT: 'app:wipe-before-quit',
+
+  // OS hostname — returns the machine hostname via Node's `os.hostname()`.
+  // Used by AuthContext on first launch to populate the `devices` row with
+  // a human-readable default device name. Returns null on failure.
+  APP_HOSTNAME: 'app:hostname',
 } as const;
 
 // ---- Screen sources ------------------------------------------------------

apps/desktop/electron/main.ts

@@ -6,11 +6,13 @@
 // the old Tauri devUrl so nothing in the renderer code needs to change)
 // and from the built dist in packaged mode.
 
-import { app, BrowserWindow, desktopCapturer, Menu, session } from 'electron';
+import { app, BrowserWindow, desktopCapturer, ipcMain, Menu, session } from 'electron';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
+import { CHANNELS } from './ipc-types';
 import { register as registerAudioLoopback } from './modules/audio-loopback';
+import { register as registerAppHostname } from './modules/app-hostname';
 import { register as registerAutostart } from './modules/autostart';
 import { register as registerFsScoped } from './modules/fs-scoped';
 import { register as registerNotifications } from './modules/notifications';
@@ -253,6 +255,7 @@ if (!gotLock) {
     registerFsScoped();
     registerSql();
     registerAutostart();
+    registerAppHostname();
 
     // Window-dependent registrars — only call once mainWindow exists so
     // event emitters have somewhere to send.
@@ -263,6 +266,32 @@ if (!gotLock) {
     registerAudioLoopback(mainWindow);
   });
 
+  // Wipe-on-close: when the user enables it in Settings, the renderer is given
+  // a chance to clear all sensitive caches before the app process exits. If
+  // the renderer doesn't ack within 2 seconds we force-quit anyway — better
+  // to lose the wipe than to hang the app shutdown.
+  //
+  // Note: there's a separate `before-quit` listener in modules/tray.ts that
+  // tears down the Tray instance. Electron fires both; the tray listener is
+  // synchronous and doesn't touch event.preventDefault, so it doesn't fight
+  // our deferred-quit dance here. The `wipeRequested` flag guards re-entry
+  // when our own `app.quit()` below fires `before-quit` a second time.
+  let wipeRequested = false;
+  app.on('before-quit', (event) => {
+    if (wipeRequested) return;
+    if (!mainWindow || mainWindow.isDestroyed()) return;
+    wipeRequested = true;
+    event.preventDefault();
+
+    mainWindow.webContents.send(CHANNELS.APP_WIPE_BEFORE_QUIT);
+    const done = new Promise<void>((resolve) => {
+      ipcMain.once(CHANNELS.APP_WIPE_BEFORE_QUIT + ':done', () => resolve());
+    });
+    void Promise.race([done, new Promise<void>((r) => setTimeout(r, 2000))]).finally(() => {
+      app.quit();
+    });
+  });
+
   app.on('window-all-closed', () => {
     if (process.platform !== 'darwin') app.quit();
   });

apps/desktop/electron/modules/app-hostname.ts

@@ -0,0 +1,21 @@
+// app:hostname adapter — returns the OS hostname via Node's `os.hostname()`.
+// The renderer has no Node access (contextIsolation is ON), so it must ask
+// main for this value. Used by AuthContext on first launch to populate the
+// `devices` row with a human-readable default device name.
+
+import os from 'node:os';
+
+import { ipcMain } from 'electron';
+
+import { CHANNELS } from '../ipc-types';
+
+export function register(): void {
+  ipcMain.handle(CHANNELS.APP_HOSTNAME, (): string | null => {
+    try {
+      const h = os.hostname();
+      return typeof h === 'string' && h.length > 0 ? h : null;
+    } catch {
+      return null;
+    }
+  });
+}

apps/desktop/electron/modules/tray.ts

@@ -30,6 +30,17 @@ function resolveIconPathDev(): string {
   return path.join(app.getAppPath(), 'resources', 'icon.ico');
 }
 
+// 16×16 grey square — last-ditch fallback when neither the packaged
+// nor dev icon file resolves. Tray constructor on Windows throws when
+// handed an empty NativeImage, which would tear down the whole
+// registrar before `ipcMain.handle(TRAY_UNREAD)` runs — leaving the
+// taskbar overlay badge wired but the renderer's invoke rejecting
+// with "No handler registered". A non-empty placeholder keeps the
+// constructor happy so the IPC handler always gets registered.
+const FALLBACK_TRAY_PNG_BASE64 =
+  'iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAH0lEQVR42mNk' +
+  'YGD4z0ABYBxVOKpwVOGowlGFwwoBAEnYAR9XlIldAAAAAElFTkSuQmCC';
+
 function loadTrayIcon(): NativeImage {
   for (const p of [resolveIconPath(), resolveIconPathDev()]) {
     try {
@@ -39,7 +50,7 @@ function loadTrayIcon(): NativeImage {
       /* try next */
     }
   }
-  return nativeImage.createEmpty();
+  return nativeImage.createFromBuffer(Buffer.from(FALLBACK_TRAY_PNG_BASE64, 'base64'));
 }
 
 function buildOverlay(): NativeImage {
@@ -53,35 +64,49 @@ function buildOverlay(): NativeImage {
 }
 
 export function register(mainWindow: BrowserWindow): void {
-  const icon = loadTrayIcon();
-  trayRef = new Tray(icon.isEmpty() ? nativeImage.createEmpty() : icon);
-  trayRef.setToolTip('Netralax');
+  // Tray icon is best-effort: if neither the packaged resource nor the
+  // dev path resolves (e.g. icon.ico isn't shipped under resourcesPath
+  // in packaged builds — only the app icon goes into the .exe metadata),
+  // we still want the taskbar overlay badge to work. setOverlayIcon is
+  // a BrowserWindow method, so it functions even when the systray icon
+  // creation fails.
+  try {
+    const icon = loadTrayIcon();
+    if (!icon.isEmpty()) {
+      trayRef = new Tray(icon);
+      trayRef.setToolTip('Netralax');
 
-  const menu = Menu.buildFromTemplate([
-    {
-      label: 'Open',
-      click: (): void => {
+      const menu = Menu.buildFromTemplate([
+        {
+          label: 'Open',
+          click: (): void => {
+            if (mainWindow.isDestroyed()) return;
+            if (mainWindow.isMinimized()) mainWindow.restore();
+            mainWindow.show();
+            mainWindow.focus();
+          },
+        },
+        { type: 'separator' },
+        {
+          label: 'Quit',
+          click: (): void => {
+            app.quit();
+          },
+        },
+      ]);
+      trayRef.setContextMenu(menu);
+      trayRef.on('click', (): void => {
         if (mainWindow.isDestroyed()) return;
         if (mainWindow.isMinimized()) mainWindow.restore();
-        mainWindow.show();
-        mainWindow.focus();
-      },
-    },
-    { type: 'separator' },
-    {
-      label: 'Quit',
-      click: (): void => {
-        app.quit();
-      },
-    },
-  ]);
-  trayRef.setContextMenu(menu);
-  trayRef.on('click', (): void => {
-    if (mainWindow.isDestroyed()) return;
-    if (mainWindow.isMinimized()) mainWindow.restore();
-    if (mainWindow.isVisible()) mainWindow.focus();
-    else mainWindow.show();
-  });
+        if (mainWindow.isVisible()) mainWindow.focus();
+        else mainWindow.show();
+      });
+    }
+  } catch (err: unknown) {
+    // Swallow: the overlay badge below is the user-visible bit. A missing
+    // systray icon is cosmetic and shouldn't take the unread handler with it.
+    console.warn('[tray] systray init failed, overlay badge still active', err);
+  }
 
   ipcMain.handle(
     CHANNELS.TRAY_UNREAD,

apps/desktop/electron/preload-types.d.ts

@@ -95,6 +95,17 @@ export interface ElectronAPI {
   setAutoStart: (enabled: boolean) => Promise<void>;
 
   setFullscreen: (enabled: boolean) => Promise<void>;
+
+  /** Subscribe to the main-process pre-quit notification. Used by the
+   *  "Cache beim Schließen leeren" Settings toggle. */
+  onWipeBeforeQuit: (cb: () => Promise<void>) => () => void;
+
+  /** Returns the OS hostname (via Node's `os.hostname()`). Used by
+   *  AuthContext on first launch to populate the `devices` row with a
+   *  human-readable default device name. Optional: always feature-check
+   *  via `typeof window.electronAPI?.getHostname === 'function'` because
+   *  the web build has no preload bridge. */
+  getHostname?: () => Promise<string | null>;
 }
 
 declare global {

apps/desktop/electron/preload.ts

@@ -159,6 +159,27 @@ const api = {
   // Window fullscreen ------------------------------------------------------
   setFullscreen: (enabled: boolean): Promise<void> =>
     ipcRenderer.invoke(CHANNELS.WINDOW_SET_FULLSCREEN, enabled),
+
+  // OS hostname ------------------------------------------------------------
+  getHostname: (): Promise<string | null> => ipcRenderer.invoke(CHANNELS.APP_HOSTNAME),
+
+  // Wipe-on-close ----------------------------------------------------------
+  // Subscribe to the main-process pre-quit notification. The renderer's
+  // callback does the actual wipe (memoryWipe.ts) and resolves; we ack
+  // unconditionally so main can finish quitting — better to lose the wipe
+  // than to hang the app shutdown if the callback throws.
+  onWipeBeforeQuit: (cb: () => Promise<void>): Unsubscribe => {
+    const handler = async (_evt: Electron.IpcRendererEvent): Promise<void> => {
+      try {
+        await cb();
+      } catch (err) {
+        console.warn('[wipe] renderer cb failed', err);
+      }
+      ipcRenderer.send(CHANNELS.APP_WIPE_BEFORE_QUIT + ':done');
+    };
+    ipcRenderer.on(CHANNELS.APP_WIPE_BEFORE_QUIT, handler);
+    return () => ipcRenderer.removeListener(CHANNELS.APP_WIPE_BEFORE_QUIT, handler);
+  },
 } as const;
 
 export type ElectronAPI = typeof api;

apps/desktop/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@chat-app/desktop",
-  "version": "0.18.8",
+  "version": "0.19.1",
   "private": true,
   "description": "Electron desktop client (Windows / macOS / Linux)",
   "type": "module",
@@ -25,6 +25,7 @@
     "@livekit/track-processors": "^0.7.2",
     "@supabase/supabase-js": "^2.46.0",
     "better-sqlite3": "^11.3.0",
+    "canvas-confetti": "^1.9.4",
     "electron-updater": "^6.3.0",
     "i18next": "^23.16.4",
     "libsodium-wrappers-sumo": "0.7.15",
@@ -34,10 +35,12 @@
     "react-easy-crop": "^5.5.7",
     "react-i18next": "^15.1.1",
     "react-router-dom": "^6.28.0",
+    "react-virtuoso": "^4.18.7",
     "zustand": "^5.0.1"
   },
   "devDependencies": {
     "@types/better-sqlite3": "^7.6.0",
+    "@types/canvas-confetti": "^1.9.0",
     "@types/libsodium-wrappers": "^0.7.14",
     "@types/libsodium-wrappers-sumo": "^0.8.2",
     "@types/react": "^18.3.12",
@@ -49,6 +52,7 @@
     "electron-vite": "^2.3.0",
     "postcss": "^8.4.49",
     "rimraf": "^6.0.0",
+    "rollup-plugin-visualizer": "^7.0.1",
     "tailwindcss": "^3.4.15",
     "vite": "^5.4.11"
   },

apps/desktop/src/App.tsx

@@ -4,6 +4,7 @@ import { HashRouter, Navigate, Outlet, Route, Routes } from 'react-router-dom';
 import { AppShell } from './components/AppShell';
 import { CrashToast } from './components/CrashToast';
 import { ErrorBoundary } from './components/ErrorBoundary';
+import { RemoteRevokedScreen } from './components/RemoteRevokedScreen';
 import { SpinnerIcon } from './components/icons';
 import { UpdateToast } from './components/UpdateToast';
 import { RequireAdmin, RequireAuth, RequireDevice } from './components/guards';
@@ -168,6 +169,7 @@ export function App() {
                   </Routes>
                   <UpdateToast />
                   <CrashToast />
+                  <RemoteRevokedScreen />
                 </HashRouter>
               </CallProvider>
             </ConversationsProvider>

apps/desktop/src/components/AppShell.tsx

@@ -2,10 +2,12 @@ import { useEffect } from 'react';
 import { Outlet } from 'react-router-dom';
 
 import { useAuth } from '../context/AuthContext';
+import { useIdleAutoLock } from '../hooks/useIdleAutoLock';
 import { startConversationKeySync } from '../lib/conversationKeySync';
 import { startDeviceApprovalListener } from '../lib/deviceApproval';
 import { ensureInstallId } from '../lib/installId';
 import { ensureNotificationPermission } from '../lib/osNotify';
+import { useMentionNotifications } from '../lib/useMentionNotifications';
 import { cachedUserKey } from '../lib/userIdentity';
 import { CallUI } from './CallUI';
 import { DeviceApprovalBanner } from './DeviceApprovalBanner';
@@ -13,6 +15,8 @@ import { Sidebar } from './Sidebar';
 
 export function AppShell() {
   const { session } = useAuth();
+  useIdleAutoLock();
+  useMentionNotifications(session?.user.id);
   useEffect(() => {
     // Prompt once per authenticated shell mount. Module-level guard prevents
     // re-asking if the user already responded this session.

apps/desktop/src/components/AttachmentImage.tsx

@@ -1,13 +1,23 @@
-import { type AttachmentHandle, downloadAndDecryptAttachment } from '@chat-app/shared/chat';
+import {
+  type AttachmentHandle,
+  downloadAndDecryptAttachment,
+  downloadAndDecryptAttachmentThumb,
+} from '@chat-app/shared/chat';
 import { useEffect, useState } from 'react';
 
 import { getCachedAttachment, putCachedAttachment } from '../lib/attachmentCache';
 import { supabase } from '../lib/supabase';
 import { AlertIcon, SpinnerIcon } from './icons';
 import { Lightbox } from './Lightbox';
+import { ViewOnceImage } from './ViewOnceImage';
 
 interface Props {
   handle: AttachmentHandle;
+  /** True iff the local user sent this message. View-once images use this
+   *  to suppress the burn (senders never burn their own attachment) and to
+   *  pick the right preview chrome. Defaults to false so existing callers
+   *  (e.g. MediaFilesDrawer) keep working without modification. */
+  mine?: boolean;
 }
 
 // Max inline-preview dimension. Full-resolution stays available for the
@@ -44,12 +54,23 @@ async function makeThumbnail(blob: Blob): Promise<Blob | null> {
   }
 }
 
-export function AttachmentImage({ handle }: Props) {
+export function AttachmentImage({ handle, mine = false }: Props) {
   const [fullUrl, setFullUrl] = useState<string | null>(null);
   const [thumbUrl, setThumbUrl] = useState<string | null>(null);
   const [error, setError] = useState<string | null>(null);
   const [lightboxOpen, setLightboxOpen] = useState(false);
 
+  // Whether the sender shipped a pre-built WebP thumb alongside this attachment
+  // (Phase 6B+). When true we render the bubble from just the thumb and only
+  // fetch the full blob when the user opens the lightbox or for view-once.
+  const hasServerThumb = Boolean(handle.thumbStoragePath && handle.thumbNonceB64);
+  // View-once needs the full blob ready instantly the moment the recipient
+  // taps (otherwise we'd show a spinner during the burn animation, then race
+  // the "mark viewed" RPC). Same for the legacy path with no server thumb —
+  // we have to download the whole thing just to render the client-side
+  // makeThumbnail fallback.
+  const needsEagerFull = handle.viewOnce === true || !hasServerThumb;
+
   useEffect(() => {
     let cancelled = false;
     const created: string[] = [];
@@ -63,9 +84,39 @@ export function AttachmentImage({ handle }: Props) {
       return u;
     };
 
-    // OPFS cache → decrypt → generate thumbnail for inline display.
-    // Lightbox swaps to the full blob when opened.
+    const thumbCacheId = handle.id + '-thumb';
+
     void (async () => {
+      // Phase 6B fast path: if the sender shipped a server-side WebP thumb,
+      // grab it first so the bubble paints from ~20KB instead of waiting on
+      // the multi-MB full blob. The OPFS cache is keyed separately so the
+      // thumb survives independent of full-blob eviction.
+      if (hasServerThumb) {
+        try {
+          let thumbBlob: Blob | null = await getCachedAttachment(thumbCacheId);
+          if (!thumbBlob) {
+            thumbBlob = await downloadAndDecryptAttachmentThumb({
+              client: supabase,
+              handle,
+            });
+            if (thumbBlob) void putCachedAttachment(thumbCacheId, thumbBlob);
+          }
+          if (cancelled) return;
+          if (thumbBlob) {
+            setThumbUrl(take(thumbBlob));
+          }
+        } catch (err: unknown) {
+          // Thumb decrypt failure isn't fatal — fall through to the full
+          // blob path below so the user still sees the image.
+          console.warn('thumb load failed', err);
+        }
+      }
+
+      // Eagerly resolve the full blob when we need it for view-once or as
+      // the only render source (no server thumb). For the thumb-first path
+      // the full blob is deferred until the lightbox opens (see below).
+      if (!needsEagerFull) return;
+
       const cached = await getCachedAttachment(handle.id);
       let blob: Blob;
       if (cached) {
@@ -84,10 +135,14 @@ export function AttachmentImage({ handle }: Props) {
       if (cancelled) return;
       const full = take(blob);
       setFullUrl(full);
-      const thumb = await makeThumbnail(blob);
-      if (cancelled) return;
-      if (thumb) {
-        setThumbUrl(take(thumb));
+      // Pre-Phase-6B fallback: no server thumb shipped, so re-derive a
+      // smaller preview on the client to keep memory pressure down.
+      if (!hasServerThumb) {
+        const thumb = await makeThumbnail(blob);
+        if (cancelled) return;
+        if (thumb) {
+          setThumbUrl(take(thumb));
+        }
       }
     })();
 
@@ -95,7 +150,51 @@ export function AttachmentImage({ handle }: Props) {
       cancelled = true;
       for (const u of created) URL.revokeObjectURL(u);
     };
-  }, [handle.id, handle.storagePath, handle.keyB64, handle.nonceB64]);
+  }, [
+    handle,
+    handle.id,
+    handle.storagePath,
+    handle.keyB64,
+    handle.nonceB64,
+    handle.thumbStoragePath,
+    handle.thumbNonceB64,
+    hasServerThumb,
+    needsEagerFull,
+  ]);
+
+  // Lazy full-image fetch for click-to-expand (only kicks in when we
+  // skipped the eager full-blob download above). Resolves into the same
+  // `fullUrl` state that the Lightbox consumes; the thumb URL keeps
+  // backing the bubble until the lightbox actually mounts.
+  useEffect(() => {
+    if (!lightboxOpen) return;
+    if (fullUrl) return;
+    let cancelled = false;
+    const created: string[] = [];
+    void (async () => {
+      const cached = await getCachedAttachment(handle.id);
+      let blob: Blob;
+      if (cached) {
+        blob = cached;
+      } else {
+        try {
+          blob = await downloadAndDecryptAttachment({ client: supabase, handle });
+          void putCachedAttachment(handle.id, blob);
+        } catch (err: unknown) {
+          if (!cancelled) setError(err instanceof Error ? err.message : 'download failed');
+          return;
+        }
+      }
+      if (cancelled) return;
+      const u = URL.createObjectURL(blob);
+      created.push(u);
+      setFullUrl(u);
+    })();
+    return () => {
+      cancelled = true;
+      for (const u of created) URL.revokeObjectURL(u);
+    };
+  }, [lightboxOpen, fullUrl, handle]);
 
   const blobUrl = thumbUrl ?? fullUrl;
 
@@ -116,6 +215,25 @@ export function AttachmentImage({ handle }: Props) {
     );
   }
 
+  // View-once attachments swap the standard image preview for the ViewOnceImage
+  // chrome (locked card → fullscreen lightbox + burn for recipient, normal
+  // image with badge for sender). We still kick off the decrypt above so the
+  // fullscreen lightbox has the decoded blob ready the moment the recipient
+  // taps. `handle.viewedAt` is undefined in the current renderer (it lives on
+  // the public attachment row, not in the encrypted payload) — the component
+  // treats undefined as "not yet burned" and uses the RPC response to flip
+  // the state locally after the recipient opens.
+  if (handle.viewOnce) {
+    return (
+      <ViewOnceImage
+        attachmentId={handle.id}
+        viewedAt={handle.viewedAt ?? null}
+        isSender={mine}
+        src={blobUrl}
+      />
+    );
+  }
+
   return (
     <>
       <button
@@ -132,7 +250,15 @@ export function AttachmentImage({ handle }: Props) {
           className="block h-auto max-h-80 w-auto max-w-full object-contain"
         />
       </button>
-      {lightboxOpen && fullUrl && <Lightbox url={fullUrl} onClose={() => setLightboxOpen(false)} />}
+      {lightboxOpen && (
+        <Lightbox
+          // Prefer the full blob the moment it's available; otherwise show
+          // the thumb so the user sees *something* during the lazy fetch
+          // (typical full-blob fetch is 100ms–2s depending on size).
+          url={fullUrl ?? blobUrl}
+          onClose={() => setLightboxOpen(false)}
+        />
+      )}
     </>
   );
 }

apps/desktop/src/components/Avatar.tsx

@@ -11,6 +11,11 @@ interface Props {
   // brand-tinted fallback; callers can override (e.g. to colour-by-id).
   fallbackClass?: string;
   alt?: string;
+  // Browser loading hint. Use 'eager' for above-the-fold avatars (e.g. the
+  // active conversation header, call tiles). Defaults to 'lazy' so off-screen
+  // avatars (chat list rows, friends list, popovers) don't hammer Supabase
+  // Storage on initial render.
+  loading?: 'eager' | 'lazy';
 }
 
 export function Avatar({
@@ -19,6 +24,7 @@ export function Avatar({
   className = 'h-10 w-10',
   fallbackClass = 'bg-accent/20 text-accent',
   alt,
+  loading = 'lazy',
 }: Props) {
   const effectiveUrl = useCachedAvatarUrl(url);
   if (effectiveUrl) {
@@ -28,6 +34,7 @@ export function Avatar({
         alt={alt ?? displayName ?? ''}
         className={'shrink-0 rounded-full object-cover ' + className}
         draggable={false}
+        loading={loading}
       />
     );
   }

apps/desktop/src/components/CallParticipantTile.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useRef } from 'react';
 
+import { useNickname } from '../lib/friendNicknames';
 import {
   CrownIcon,
   HeadphonesOffIcon,
@@ -89,6 +90,7 @@ export interface ParticipantTileProps {
 
 export function CallParticipantTile(props: ParticipantTileProps) {
   const {
+    userId,
     displayName,
     me,
     muted,
@@ -107,6 +109,13 @@ export function CallParticipantTile(props: ParticipantTileProps) {
     onContextMenu,
   } = props;
 
+  // Apply the per-viewer nickname override once at the top — each tile is
+  // already per-participant, so a single hook call is fine. The resolved
+  // name is forwarded into the avatar sub-components below so their initial
+  // letter respects the nickname too.
+  const resolvedName = useNickname(userId, displayName);
+  const tileProps = { ...props, displayName: resolvedName };
+
   const small = size === 'small';
   // Discord-style: full tile border switches to emerald the whole time the
   // user is speaking. Same treatment for audio + video tiles so the visual
@@ -132,9 +141,9 @@ export function CallParticipantTile(props: ParticipantTileProps) {
       }
     >
       {video ? (
-        <VideoStub {...props} small={small} fit={focused ? 'contain' : 'cover'} />
+        <VideoStub {...tileProps} small={small} fit={focused ? 'contain' : 'cover'} />
       ) : (
-        <AudioContent {...props} small={small} />
+        <AudioContent {...tileProps} small={small} />
       )}
 
       {speaking && (
@@ -187,7 +196,7 @@ export function CallParticipantTile(props: ParticipantTileProps) {
             />
           )}
           <span className="truncate">
-            {displayName}
+            {resolvedName}
             {me ? ' (du)' : ''}
           </span>
           {e2ee && (
@@ -282,6 +291,7 @@ function AudioContent({
             src={avatarUrl}
             alt=""
             className="relative h-full w-full rounded-full object-cover"
+            loading="eager"
           />
         ) : (
           <span
@@ -357,7 +367,7 @@ function VideoStub({
         }
       >
         {avatarUrl ? (
-          <img src={avatarUrl} alt="" className="h-full w-full rounded-full object-cover" />
+          <img src={avatarUrl} alt="" className="h-full w-full rounded-full object-cover" loading="eager" />
         ) : (
           letter
         )}

apps/desktop/src/components/ConnectFourBoard.tsx

@@ -0,0 +1,61 @@
+import {
+  C4_COLS,
+  C4_ROWS,
+  c4DropRow,
+  c4WinningCells,
+  type Cell,
+} from '@chat-app/shared/chat';
+
+interface Props {
+  board: Cell[];
+  myPlayerIdx: 0 | 1 | null;
+  disabled: boolean;
+  onMove: (column: number) => void;
+}
+
+export function ConnectFourBoard({ board, myPlayerIdx, disabled, onMove }: Props) {
+  const winCells = c4WinningCells(board);
+  const winSet = new Set<number>(winCells ?? []);
+
+  return (
+    <div
+      className="mx-auto w-full max-w-2xl rounded-2xl bg-sky-900/40 p-3"
+      role="grid"
+      aria-label="Vier-Gewinnt"
+    >
+      <div
+        className="grid gap-1.5"
+        style={{ gridTemplateColumns: 'repeat(' + C4_COLS + ', minmax(0, 1fr))' }}
+      >
+        {Array.from({ length: C4_ROWS * C4_COLS }, (_, idx) => {
+          const cell = board[idx];
+          const col = idx % C4_COLS;
+          const dropTo = c4DropRow(board, col);
+          const canClickColumn = !disabled && dropTo >= 0 && myPlayerIdx !== null;
+          const inWin = winSet.has(idx);
+          return (
+            <button
+              key={idx}
+              type="button"
+              onClick={() => canClickColumn && onMove(col)}
+              disabled={!canClickColumn}
+              aria-label={'Spalte ' + (col + 1) + (cell !== null ? ' belegt' : '')}
+              className={
+                'flex aspect-square items-center justify-center rounded-full border-2 transition ' +
+                (inWin
+                  ? 'border-emerald-300 bg-emerald-400 shadow-[0_0_12px_rgba(110,231,183,0.7)]'
+                  : cell === 0
+                    ? 'border-rose-300 bg-rose-500'
+                    : cell === 1
+                      ? 'border-amber-300 bg-amber-400'
+                      : canClickColumn
+                        ? 'cursor-pointer border-sky-700 bg-sky-950 hover:bg-sky-900'
+                        : 'cursor-not-allowed border-sky-800 bg-sky-950 opacity-80')
+              }
+            />
+          );
+        })}
+      </div>
+    </div>
+  );
+}

apps/desktop/src/components/ConversationHeader.tsx

@@ -3,6 +3,7 @@ import type { PresenceState } from '@chat-app/shared/supabase';
 import { useTranslation } from 'react-i18next';
 
 import { useCall } from '../context/CallContext';
+import { useNickname } from '../lib/friendNicknames';
 import type { PeerPresence } from '../lib/usePeerPresence';
 import { Avatar } from './Avatar';
 import {
@@ -13,6 +14,7 @@ import {
   UsersIcon,
   VideoIcon,
 } from './icons';
+import { PinnedMessagesPill } from './PinnedMessagesPill';
 
 const PRESENCE_DOT: Record<PresenceState, string> = {
   online: 'bg-emerald-500',
@@ -29,6 +31,8 @@ interface Props {
   onMediaClick?: () => void;
   onProfileClick?: (ev: React.MouseEvent) => void;
   onSearchClick?: () => void;
+  pinnedCount?: number;
+  onOpenPinned?: () => void;
 }
 
 export function ConversationHeader({
@@ -38,6 +42,8 @@ export function ConversationHeader({
   onMediaClick,
   onProfileClick,
   onSearchClick,
+  pinnedCount = 0,
+  onOpenPinned,
 }: Props) {
   if (!conversation) {
     return <header className="h-[65px] border-b border-line px-6 py-3" aria-busy="true" />;
@@ -48,10 +54,12 @@ export function ConversationHeader({
       <HeaderBar
         conversation={conversation}
         peerPresence={peerPresence}
+        pinnedCount={pinnedCount}
         {...(onInfoClick ? { onInfoClick } : {})}
         {...(onMediaClick ? { onMediaClick } : {})}
         {...(onProfileClick ? { onProfileClick } : {})}
         {...(onSearchClick ? { onSearchClick } : {})}
+        {...(onOpenPinned ? { onOpenPinned } : {})}
       />
       {/* Voice-channel rail rendered separately in ConversationPage so it
           can sit between the message surface and the in-call dock. */}
@@ -66,6 +74,8 @@ interface HeaderBarProps {
   onMediaClick?: () => void;
   onProfileClick?: (ev: React.MouseEvent) => void;
   onSearchClick?: () => void;
+  pinnedCount?: number;
+  onOpenPinned?: () => void;
 }
 
 function HeaderBar({
@@ -75,11 +85,19 @@ function HeaderBar({
   onMediaClick,
   onProfileClick,
   onSearchClick,
+  pinnedCount = 0,
+  onOpenPinned,
 }: HeaderBarProps) {
   const { t } = useTranslation(['app']);
 
   const isDm = conversation.type === 'dm';
-  const title = isDm ? (conversation.peer?.displayName ?? '?') : (conversation.name ?? '?');
+  // For DMs, route the peer's display name through the per-viewer nickname
+  // override. Falls back to the real displayName when no nickname is set.
+  const peerName = useNickname(
+    conversation.peer?.userId,
+    conversation.peer?.displayName ?? '?',
+  );
+  const title = isDm ? peerName : (conversation.name ?? '?');
   const handle = isDm ? '@' + (conversation.peer?.username ?? '?') : '';
   const peerAvatar = isDm
     ? (conversation.peer?.avatarUrl ?? null)
@@ -111,9 +129,9 @@ function HeaderBar({
         className="relative shrink-0 rounded-full text-left transition enabled:cursor-pointer enabled:hover:ring-2 enabled:hover:ring-accent/50 focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/50 disabled:cursor-default"
       >
         {isDm ? (
-          <Avatar url={peerAvatar} displayName={title} className="h-10 w-10 text-base" />
+          <Avatar url={peerAvatar} displayName={title} className="h-10 w-10 text-base" loading="eager" />
         ) : peerAvatar ? (
-          <Avatar url={peerAvatar} displayName={title} className="h-10 w-10 text-base" />
+          <Avatar url={peerAvatar} displayName={title} className="h-10 w-10 text-base" loading="eager" />
         ) : (
           <div className="flex h-10 w-10 items-center justify-center rounded-full bg-accent/20 text-accent">
             <UsersIcon className="h-5 w-5" />
@@ -133,6 +151,7 @@ function HeaderBar({
         <div className="flex min-w-0 items-center gap-2">
           {!isDm && <UsersIcon className="h-4 w-4 shrink-0 text-fg-muted" />}
           <p className="truncate font-display text-base font-semibold text-fg">{title}</p>
+          <PinnedMessagesPill count={pinnedCount} onClick={() => onOpenPinned?.()} />
         </div>
         <p className="truncate text-xs text-fg-muted">
           {isDm ? (
@@ -178,7 +197,7 @@ function HeaderBar({
 
 interface HeaderActionButtonProps {
   label: string;
-  icon: (props: React.SVGProps<SVGSVGElement>) => React.JSX.Element;
+  icon: React.ComponentType<React.ComponentPropsWithoutRef<'svg'>>;
   onClick?: () => void;
   disabled?: boolean;
   tone?: 'default' | 'accent';

apps/desktop/src/components/ConversationRowMenu.tsx

@@ -1,19 +1,22 @@
 import {
   muteDurationToIso,
   setConversationArchived,
+  setConversationMentionsOnly,
   setConversationMutedUntil,
 } from '@chat-app/shared/chat';
 import { forwardRef, useCallback, useEffect, useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
 import { useTranslation } from 'react-i18next';
 
+import { useConversationsContext } from '../context/ConversationsContext';
 import { supabase } from '../lib/supabase';
-import { ArchiveIcon, BellIcon, BellOffIcon, MoreVerticalIcon } from './icons';
+import { ArchiveIcon, AtIcon, BellIcon, BellOffIcon, MoreVerticalIcon } from './icons';
 
 interface Props {
   conversationId: string;
   archived: boolean;
   mutedUntil: string | null;
+  mentionsOnly: boolean;
 }
 
 interface MuteOption {
@@ -50,8 +53,9 @@ interface MenuPos {
 // escape the sidebar's `overflow-y-auto` clipping context. Position is
 // computed from the trigger's bounding rect — menu anchors right-aligned
 // under the trigger so it doesn't push off-screen on narrow windows.
-export function ConversationRowMenu({ conversationId, archived, mutedUntil }: Props) {
+export function ConversationRowMenu({ conversationId, archived, mutedUntil, mentionsOnly }: Props) {
   const { t } = useTranslation(['app']);
+  const { patchConversation } = useConversationsContext();
   const [open, setOpen] = useState(false);
   const [submenuOpen, setSubmenuOpen] = useState<'mute' | null>(null);
   const [menuPos, setMenuPos] = useState<MenuPos | null>(null);
@@ -120,29 +124,59 @@ export function ConversationRowMenu({ conversationId, archived, mutedUntil }: Pr
   const isMuted =
     mutedUntil !== null && new Date(mutedUntil).getTime() > Date.now();
 
+  // Optimistic updates: flip the local state before the server RPC so the
+  // bell / archive icon / checkmark update on the same frame as the click.
+  // Realtime echo via ConversationsContext will reconcile (no-op since the
+  // optimistic patch already matches the server row). On error we restore
+  // the previous value so the menu doesn't lie about persisted state.
   const handleArchive = useCallback(
     async (next: boolean) => {
       setOpen(false);
+      const previous = archived;
+      patchConversation(conversationId, { archived: next });
       try {
         await setConversationArchived(supabase, conversationId, next);
       } catch (err: unknown) {
+        patchConversation(conversationId, { archived: previous });
         console.error('archive toggle failed', err);
       }
     },
-    [conversationId],
+    [conversationId, archived, patchConversation],
   );
 
   const handleMute = useCallback(
     async (minutes: number | null) => {
       setOpen(false);
       setSubmenuOpen(null);
+      const previous = mutedUntil;
+      const nextIso = muteDurationToIso(minutes);
+      patchConversation(conversationId, { mutedUntil: nextIso });
       try {
-        await setConversationMutedUntil(supabase, conversationId, muteDurationToIso(minutes));
+        await setConversationMutedUntil(supabase, conversationId, nextIso);
       } catch (err: unknown) {
+        patchConversation(conversationId, { mutedUntil: previous });
         console.error('mute toggle failed', err);
       }
     },
-    [conversationId],
+    [conversationId, mutedUntil, patchConversation],
+  );
+
+  const handleMentionsOnly = useCallback(
+    async (next: boolean) => {
+      setOpen(false);
+      const previous = mentionsOnly;
+      patchConversation(conversationId, { mentionsOnly: next });
+      try {
+        await setConversationMentionsOnly(supabase, {
+          conversationId,
+          mentionsOnly: next,
+        });
+      } catch (err: unknown) {
+        patchConversation(conversationId, { mentionsOnly: previous });
+        console.warn('mentions-only toggle failed', err);
+      }
+    },
+    [conversationId, mentionsOnly, patchConversation],
   );
 
   return (
@@ -196,6 +230,16 @@ export function ConversationRowMenu({ conversationId, archived, mutedUntil }: Pr
               }}
               hasSubmenu={!isMuted}
             />
+            <MenuItem
+              icon={<AtIcon className="h-4 w-4" />}
+              label={
+                (mentionsOnly ? '✓ ' : '') +
+                t('app:chats.mentions_only', {
+                  defaultValue: 'Nur bei @Mentions benachrichtigen',
+                })
+              }
+              onClick={() => void handleMentionsOnly(!mentionsOnly)}
+            />
           </div>,
           document.body,
         )}

apps/desktop/src/components/EmptyState.tsx

@@ -0,0 +1,32 @@
+import type { ReactNode } from 'react';
+
+interface Props {
+  icon: ReactNode;
+  title: string;
+  description: string;
+  action?: { label: string; onClick: () => void };
+}
+
+// Reusable empty-state placeholder: large icon + heading + description +
+// optional primary CTA. Used everywhere there's a meaningfully-empty list
+// (no chats, no friends, no search results, fresh conversation).
+export function EmptyState({ icon, title, description, action }: Props) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center px-6 py-12 text-center">
+      <div className="mb-4 flex h-16 w-16 items-center justify-center rounded-2xl bg-accent/10 text-accent">
+        {icon}
+      </div>
+      <h3 className="font-display text-lg font-semibold text-fg">{title}</h3>
+      <p className="mt-2 max-w-xs text-sm text-fg-muted">{description}</p>
+      {action && (
+        <button
+          type="button"
+          onClick={action.onClick}
+          className="mt-5 inline-flex cursor-pointer items-center justify-center rounded-lg bg-accent px-4 py-2 text-sm font-semibold text-accent-fg transition hover:brightness-110 focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
+        >
+          {action.label}
+        </button>
+      )}
+    </div>
+  );
+}

apps/desktop/src/components/GameModal.tsx

@@ -0,0 +1,133 @@
+import confetti from 'canvas-confetti';
+import { useEffect } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useAuth } from '../context/AuthContext';
+import { useGame } from '../hooks/useGame';
+import { ConnectFourBoard } from './ConnectFourBoard';
+import { TicTacToeBoard } from './TicTacToeBoard';
+import { XIcon } from './icons';
+
+interface Props {
+  gameId: string;
+  onClose: () => void;
+}
+
+export function GameModal({ gameId, onClose }: Props) {
+  const { t } = useTranslation();
+  const { game, loading, error, makeMove } = useGame(gameId);
+  const { session: auth } = useAuth();
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [onClose]);
+
+  const myUserId = auth?.user.id ?? null;
+  const myPlayerIdx: 0 | 1 | null =
+    !game || !myUserId
+      ? null
+      : game.players[0] === myUserId
+        ? 0
+        : game.players[1] === myUserId
+          ? 1
+          : null;
+  const isMyTurn = !!game && game.currentTurnUserId === myUserId;
+  const finished = !!game?.finishedAt;
+  const winnerIdx: 0 | 1 | null =
+    !game?.winnerUserId
+      ? null
+      : game.players[0] === game.winnerUserId
+        ? 0
+        : game.players[1] === game.winnerUserId
+          ? 1
+          : null;
+
+  useEffect(() => {
+    if (finished && winnerIdx !== null && winnerIdx === myPlayerIdx) {
+      // Respect the OS-level reduced-motion preference.
+      if (
+        typeof window !== 'undefined' &&
+        window.matchMedia &&
+        window.matchMedia('(prefers-reduced-motion: reduce)').matches
+      ) {
+        return;
+      }
+      // Two bursts from the lower corners for a celebratory feel.
+      void confetti({
+        particleCount: 80,
+        spread: 60,
+        origin: { x: 0.2, y: 0.9 },
+      });
+      void confetti({
+        particleCount: 80,
+        spread: 60,
+        origin: { x: 0.8, y: 0.9 },
+      });
+    }
+  }, [finished, winnerIdx, myPlayerIdx]);
+  const title =
+    game?.gameType === 'c4'
+      ? t('app:game.c4', { defaultValue: 'Vier-Gewinnt' })
+      : t('app:game.ttt', { defaultValue: 'Tic-Tac-Toe' });
+
+  const statusLine = (() => {
+    if (loading) return t('app:game.loading', { defaultValue: 'Lädt…' });
+    if (error) return error;
+    if (!game) return t('app:game.missing', { defaultValue: 'Spiel nicht gefunden.' });
+    if (finished) {
+      if (winnerIdx === null) return t('app:game.draw', { defaultValue: 'Unentschieden!' });
+      if (winnerIdx === myPlayerIdx) return t('app:game.you_win', { defaultValue: 'Du hast gewonnen!' });
+      return t('app:game.you_lose', { defaultValue: 'Du hast verloren.' });
+    }
+    if (myPlayerIdx === null) return t('app:game.spectator', { defaultValue: 'Du schaust nur zu.' });
+    if (isMyTurn) return t('app:game.your_turn', { defaultValue: 'Du bist dran' });
+    return t('app:game.opponent_turn', { defaultValue: 'Gegner ist dran…' });
+  })();
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label={title}
+      className="fixed inset-0 z-[80] flex flex-col bg-ink-950/95"
+    >
+      <header className="flex shrink-0 items-center justify-between border-b border-line/40 bg-surface-2 px-4 py-2">
+        <h2 className="font-display text-sm font-semibold text-fg">{title}</h2>
+        <button
+          type="button"
+          onClick={onClose}
+          aria-label={t('app:game.close', { defaultValue: 'Schließen' })}
+          className="flex h-7 w-7 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </header>
+
+      <div className="flex min-h-0 flex-1 items-center justify-center overflow-auto p-6">
+        {game?.gameType === 'ttt' ? (
+          <TicTacToeBoard
+            board={game.state.board}
+            myPlayerIdx={myPlayerIdx}
+            disabled={!isMyTurn || finished}
+            onMove={(cell) => void makeMove({ cell }).catch(() => {})}
+          />
+        ) : game?.gameType === 'c4' ? (
+          <ConnectFourBoard
+            board={game.state.board}
+            myPlayerIdx={myPlayerIdx}
+            disabled={!isMyTurn || finished}
+            onMove={(column) => void makeMove({ column }).catch(() => {})}
+          />
+        ) : null}
+      </div>
+
+      <footer className="flex shrink-0 items-center justify-center border-t border-line/40 bg-surface-2 px-4 py-3 text-sm font-medium text-fg">
+        {statusLine}
+      </footer>
+    </div>
+  );
+}

apps/desktop/src/components/GifPicker.tsx

@@ -0,0 +1,126 @@
+import { useEffect, useMemo, useState } from 'react';
+
+import {
+  featuredGifs,
+  getRecentGifs,
+  type GifResult,
+  rememberRecentGif,
+  searchGifs,
+} from '../lib/tenor';
+import { SpinnerIcon, XIcon } from './icons';
+
+interface Props {
+  open: boolean;
+  onClose: () => void;
+  onPick: (gif: GifResult) => void;
+}
+
+type Tab = 'trending' | 'search' | 'recent';
+
+export function GifPicker({ open, onClose, onPick }: Props) {
+  const [tab, setTab] = useState<Tab>('trending');
+  const [query, setQuery] = useState('');
+  const [results, setResults] = useState<GifResult[]>([]);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const recent = useMemo(() => getRecentGifs(), [open]);
+
+  useEffect(() => {
+    if (!open) return;
+    let cancelled = false;
+    setLoading(true);
+    setError(null);
+    const run = async () => {
+      try {
+        const gifs = tab === 'search' && query.trim().length > 0
+          ? await searchGifs(query)
+          : tab === 'trending'
+            ? await featuredGifs()
+            : [];
+        if (!cancelled) setResults(gifs);
+      } catch (err) {
+        if (!cancelled) setError(err instanceof Error ? err.message : 'GIFs gerade nicht verfügbar');
+      } finally {
+        if (!cancelled) setLoading(false);
+      }
+    };
+    void run();
+    return () => { cancelled = true; };
+  }, [open, tab, query]);
+
+  if (!open) return null;
+
+  const visible = tab === 'recent' ? recent : results;
+
+  return (
+    <div className="absolute bottom-full left-0 z-30 mb-2 w-[440px] rounded-2xl border border-line bg-surface-2 shadow-xl">
+      <header className="flex items-center justify-between border-b border-line px-3 py-2">
+        <div className="flex items-center gap-1">
+          {(['trending', 'search', 'recent'] as Tab[]).map((t) => (
+            <button
+              key={t}
+              type="button"
+              onClick={() => setTab(t)}
+              className={
+                'cursor-pointer rounded-md px-2 py-1 text-xs font-medium transition ' +
+                (t === tab ? 'bg-accent/15 text-accent' : 'text-fg-muted hover:text-fg')
+              }
+            >
+              {t === 'trending' ? 'Trending' : t === 'search' ? 'Suche' : 'Zuletzt'}
+            </button>
+          ))}
+        </div>
+        <button
+          type="button"
+          onClick={onClose}
+          aria-label="Schließen"
+          className="flex h-6 w-6 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </header>
+      {tab === 'search' && (
+        <div className="border-b border-line px-3 py-2">
+          <input
+            type="text"
+            value={query}
+            onChange={(e) => setQuery(e.target.value)}
+            placeholder="GIFs suchen…"
+            className="w-full rounded-md border border-line bg-surface-3 px-2 py-1.5 text-sm text-fg placeholder-fg-muted focus:border-accent focus:outline-none focus:ring-1 focus:ring-accent/40"
+          />
+        </div>
+      )}
+      <div className="grid max-h-[360px] grid-cols-3 gap-1.5 overflow-y-auto p-2">
+        {loading && (
+          <div className="col-span-3 flex justify-center py-6 text-fg-muted">
+            <SpinnerIcon className="h-5 w-5" />
+          </div>
+        )}
+        {error && (
+          <p className="col-span-3 px-2 py-4 text-center text-xs text-rose-300">
+            {error === 'giphy_api_key_missing'
+              ? 'GIFs sind nicht konfiguriert (VITE_GIPHY_API_KEY fehlt).'
+              : 'GIFs gerade nicht verfügbar.'}
+          </p>
+        )}
+        {!loading && !error && visible.length === 0 && (
+          <p className="col-span-3 px-2 py-6 text-center text-xs text-fg-muted">
+            {tab === 'recent' ? 'Noch keine zuletzt verwendeten GIFs.' : 'Keine Treffer.'}
+          </p>
+        )}
+        {!loading && !error && visible.map((g) => (
+          <button
+            key={g.id}
+            type="button"
+            onClick={() => { rememberRecentGif(g); onPick(g); onClose(); }}
+            className="overflow-hidden rounded-md border border-line bg-surface-3 hover:border-accent/40"
+            title={g.description}
+          >
+            <img src={g.previewUrl} alt={g.description || 'GIF'} className="h-24 w-full object-cover" loading="lazy" />
+          </button>
+        ))}
+      </div>
+    </div>
+  );
+}

apps/desktop/src/components/ImageAnnotator.tsx

@@ -0,0 +1,468 @@
+import { useEffect, useRef, useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { XIcon } from './icons';
+
+export type AnnotatorTool = 'pen' | 'arrow' | 'rect' | 'circle' | 'text' | 'highlighter';
+export type AnnotatorColor = '#ef4444' | '#3b82f6' | '#22c55e' | '#facc15' | '#a855f7' | '#ffffff';
+export type AnnotatorWidth = 2 | 4 | 8;
+
+export interface AnnotatorOp {
+  tool: AnnotatorTool;
+  color: AnnotatorColor;
+  width: AnnotatorWidth;
+  points?: Array<{ x: number; y: number }>;
+  from?: { x: number; y: number };
+  to?: { x: number; y: number };
+  text?: string;
+  at?: { x: number; y: number };
+}
+
+interface Props {
+  file: File;
+  onCancel: () => void;
+  onSave: (next: File) => void;
+}
+
+export function ImageAnnotator({ file, onCancel, onSave }: Props) {
+  const { t } = useTranslation();
+  const canvasRef = useRef<HTMLCanvasElement | null>(null);
+  const imageRef = useRef<HTMLImageElement | null>(null);
+  const [imageLoaded, setImageLoaded] = useState(false);
+  const [ops, setOps] = useState<AnnotatorOp[]>([]);
+  const [redoStack, setRedoStack] = useState<AnnotatorOp[]>([]);
+  // tool/color/width are read by Task 2 (drawing engine) and Task 3 (toolbar).
+  // Defaults shown here are intentional so T2's pointer handlers work
+  // immediately with sensible behavior before T3's UI is wired.
+  const [tool, setTool] = useState<AnnotatorTool>('pen');
+  const [color, setColor] = useState<AnnotatorColor>('#ef4444');
+  const [width, setWidth] = useState<AnnotatorWidth>(4);
+
+  const draftRef = useRef<AnnotatorOp | null>(null);
+  const [draftTick, setDraftTick] = useState(0);
+
+  useEffect(() => {
+    const url = URL.createObjectURL(file);
+    const img = new Image();
+    img.onload = () => {
+      imageRef.current = img;
+      setImageLoaded(true);
+    };
+    img.onerror = () => {
+      console.error('ImageAnnotator: failed to decode source image');
+      onCancel();
+    };
+    img.src = url;
+    return () => URL.revokeObjectURL(url);
+  }, [file, onCancel]);
+
+  useEffect(() => {
+    if (!imageLoaded) return;
+    const cv = canvasRef.current;
+    const img = imageRef.current;
+    if (!cv || !img) return;
+    cv.width = img.naturalWidth;
+    cv.height = img.naturalHeight;
+    const ctx = cv.getContext('2d');
+    if (!ctx) return;
+    ctx.drawImage(img, 0, 0);
+    for (const op of ops) {
+      renderOp(ctx, op);
+    }
+    if (draftRef.current) {
+      renderOp(ctx, draftRef.current);
+    }
+  }, [imageLoaded, ops, draftTick]);
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onCancel();
+      if ((e.ctrlKey || e.metaKey) && e.key === 'z' && !e.shiftKey) {
+        e.preventDefault();
+        handleUndo();
+      } else if ((e.ctrlKey || e.metaKey) && (e.key === 'y' || (e.key === 'z' && e.shiftKey))) {
+        e.preventDefault();
+        handleRedo();
+      }
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  });
+
+  const handleUndo = () => {
+    setOps((cur) => {
+      if (cur.length === 0) return cur;
+      const next = cur.slice(0, -1);
+      setRedoStack((r) => [...r, cur[cur.length - 1]!]);
+      return next;
+    });
+  };
+
+  const handleRedo = () => {
+    setRedoStack((r) => {
+      if (r.length === 0) return r;
+      const top = r[r.length - 1]!;
+      setOps((cur) => [...cur, top]);
+      return r.slice(0, -1);
+    });
+  };
+
+  const handleReset = () => {
+    setOps([]);
+    setRedoStack([]);
+  };
+
+  const handleSave = () => {
+    const cv = canvasRef.current;
+    if (!cv) return;
+    cv.toBlob((blob) => {
+      if (!blob) {
+        console.error('ImageAnnotator: toBlob returned null');
+        return;
+      }
+      const baseName = file.name.replace(/\.[^.]+$/, '');
+      const next = new File([blob], baseName + '-annotated.png', {
+        type: 'image/png',
+        lastModified: Date.now(),
+      });
+      onSave(next);
+    }, 'image/png');
+  };
+
+  function canvasPoint(e: React.PointerEvent<HTMLCanvasElement>): { x: number; y: number } {
+    const cv = canvasRef.current!;
+    const rect = cv.getBoundingClientRect();
+    const scaleX = cv.width / rect.width;
+    const scaleY = cv.height / rect.height;
+    return {
+      x: (e.clientX - rect.left) * scaleX,
+      y: (e.clientY - rect.top) * scaleY,
+    };
+  }
+
+  const handlePointerDown = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!imageLoaded) return;
+    const cv = canvasRef.current;
+    if (!cv) return;
+    cv.setPointerCapture(e.pointerId);
+    const p = canvasPoint(e);
+
+    if (tool === 'text') {
+      const value = window.prompt(
+        t('app:annotator.text_prompt', { defaultValue: 'Text eingeben:' }),
+        '',
+      );
+      if (value !== null && value.trim().length > 0) {
+        setOps((cur) => [...cur, { tool: 'text', color, width, text: value, at: p }]);
+        setRedoStack([]);
+      }
+      return;
+    }
+
+    if (tool === 'pen' || tool === 'highlighter') {
+      draftRef.current = { tool, color, width, points: [p] };
+    } else {
+      draftRef.current = { tool, color, width, from: p, to: p };
+    }
+    setDraftTick((n) => n + 1);
+  };
+
+  const handlePointerMove = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!draftRef.current) return;
+    const p = canvasPoint(e);
+    const cur = draftRef.current;
+    if (cur.tool === 'pen' || cur.tool === 'highlighter') {
+      cur.points = [...(cur.points ?? []), p];
+    } else {
+      cur.to = p;
+    }
+    setDraftTick((n) => n + 1);
+  };
+
+  const handlePointerUp = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    const cv = canvasRef.current;
+    if (cv && cv.hasPointerCapture(e.pointerId)) cv.releasePointerCapture(e.pointerId);
+    const cur = draftRef.current;
+    draftRef.current = null;
+    if (!cur) return;
+    const hasContent =
+      (cur.tool === 'pen' || cur.tool === 'highlighter')
+        ? (cur.points?.length ?? 0) >= 2
+        : !!(cur.from && cur.to && (cur.from.x !== cur.to.x || cur.from.y !== cur.to.y));
+    if (hasContent) {
+      setOps((p) => [...p, cur]);
+      setRedoStack([]);
+    }
+    setDraftTick((n) => n + 1);
+  };
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label={t('app:annotator.title', { defaultValue: 'Bild bearbeiten' })}
+      className="fixed inset-0 z-[80] flex flex-col bg-ink-950/95"
+    >
+      <header className="flex shrink-0 items-center justify-between border-b border-line/40 bg-surface-2 px-4 py-2">
+        <h2 className="font-display text-sm font-semibold text-fg">
+          {t('app:annotator.title', { defaultValue: 'Bild bearbeiten' })}
+        </h2>
+        <button
+          type="button"
+          onClick={onCancel}
+          aria-label={t('app:annotator.cancel', { defaultValue: 'Abbrechen' })}
+          className="flex h-7 w-7 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </header>
+
+      <div className="flex min-h-0 flex-1 items-center justify-center overflow-hidden p-6">
+        {imageLoaded ? (
+          <canvas
+            ref={canvasRef}
+            onPointerDown={handlePointerDown}
+            onPointerMove={handlePointerMove}
+            onPointerUp={handlePointerUp}
+            onPointerLeave={handlePointerUp}
+            className="max-h-full max-w-full cursor-crosshair touch-none rounded-lg border border-line/40 bg-black shadow-2xl"
+          />
+        ) : (
+          <p className="text-sm text-fg-muted">
+            {t('app:annotator.loading', { defaultValue: 'Bild wird geladen…' })}
+          </p>
+        )}
+      </div>
+
+      <footer className="flex shrink-0 flex-wrap items-center gap-4 border-t border-line/40 bg-surface-2 px-4 py-3">
+        <div className="flex items-center gap-1">
+          {(['pen', 'highlighter', 'arrow', 'rect', 'circle', 'text'] as AnnotatorTool[]).map((id) => {
+            const label = t('app:annotator.tool.' + id, {
+              defaultValue:
+                id === 'pen' ? 'Stift'
+                : id === 'highlighter' ? 'Marker'
+                : id === 'arrow' ? 'Pfeil'
+                : id === 'rect' ? 'Rechteck'
+                : id === 'circle' ? 'Kreis'
+                : 'Text',
+            });
+            const active = tool === id;
+            return (
+              <button
+                key={id}
+                type="button"
+                onClick={() => setTool(id)}
+                aria-pressed={active}
+                title={label}
+                className={
+                  'flex h-8 w-8 cursor-pointer items-center justify-center rounded-md text-xs font-semibold transition ' +
+                  (active
+                    ? 'bg-accent/20 text-accent ring-2 ring-accent/40'
+                    : 'bg-surface-3 text-fg-muted hover:bg-surface hover:text-fg')
+                }
+              >
+                {toolGlyph(id)}
+              </button>
+            );
+          })}
+        </div>
+
+        <div className="h-6 w-px bg-line/40" aria-hidden />
+
+        <div className="flex items-center gap-1">
+          {(['#ef4444', '#3b82f6', '#22c55e', '#facc15', '#a855f7', '#ffffff'] as AnnotatorColor[]).map((c) => {
+            const active = color === c;
+            return (
+              <button
+                key={c}
+                type="button"
+                onClick={() => setColor(c)}
+                aria-pressed={active}
+                aria-label={c}
+                className={
+                  'h-6 w-6 cursor-pointer rounded-full border-2 transition ' +
+                  (active ? 'border-fg scale-110' : 'border-line/40 hover:scale-105')
+                }
+                style={{ backgroundColor: c }}
+              />
+            );
+          })}
+        </div>
+
+        <div className="h-6 w-px bg-line/40" aria-hidden />
+
+        <div className="flex items-center gap-1">
+          {([2, 4, 8] as AnnotatorWidth[]).map((w) => {
+            const active = width === w;
+            return (
+              <button
+                key={w}
+                type="button"
+                onClick={() => setWidth(w)}
+                aria-pressed={active}
+                title={w + 'px'}
+                className={
+                  'flex h-8 w-8 cursor-pointer items-center justify-center rounded-md transition ' +
+                  (active
+                    ? 'bg-accent/20 ring-2 ring-accent/40'
+                    : 'bg-surface-3 hover:bg-surface')
+                }
+              >
+                <div
+                  className="rounded-full bg-fg"
+                  style={{ width: w + 2 + 'px', height: w + 2 + 'px' }}
+                />
+              </button>
+            );
+          })}
+        </div>
+
+        <div className="h-6 w-px bg-line/40" aria-hidden />
+
+        <div className="flex items-center gap-1">
+          <button
+            type="button"
+            onClick={handleUndo}
+            disabled={ops.length === 0}
+            title={t('app:annotator.undo', { defaultValue: 'Rückgängig (Ctrl+Z)' })}
+            className="flex h-8 w-8 cursor-pointer items-center justify-center rounded-md bg-surface-3 text-fg-muted transition hover:bg-surface hover:text-fg disabled:cursor-not-allowed disabled:opacity-40"
+          >
+            ↶
+          </button>
+          <button
+            type="button"
+            onClick={handleRedo}
+            disabled={redoStack.length === 0}
+            title={t('app:annotator.redo', { defaultValue: 'Wiederholen (Ctrl+Y)' })}
+            className="flex h-8 w-8 cursor-pointer items-center justify-center rounded-md bg-surface-3 text-fg-muted transition hover:bg-surface hover:text-fg disabled:cursor-not-allowed disabled:opacity-40"
+          >
+            ↷
+          </button>
+        </div>
+
+        <div className="ml-auto flex items-center gap-2">
+          <button
+            type="button"
+            onClick={handleReset}
+            disabled={ops.length === 0}
+            className="cursor-pointer rounded-md border border-line bg-surface-3 px-3 py-1.5 text-xs font-medium text-fg-muted transition hover:bg-surface disabled:cursor-not-allowed disabled:opacity-50"
+          >
+            {t('app:annotator.reset', { defaultValue: 'Zurücksetzen' })}
+          </button>
+          <button
+            type="button"
+            onClick={handleSave}
+            disabled={!imageLoaded}
+            className="cursor-pointer rounded-md bg-accent px-4 py-1.5 text-xs font-semibold text-accent-fg transition hover:bg-accent/90 disabled:cursor-not-allowed disabled:opacity-50"
+          >
+            {t('app:annotator.save', { defaultValue: 'Speichern' })}
+          </button>
+        </div>
+      </footer>
+    </div>
+  );
+}
+
+function toolGlyph(t: AnnotatorTool): string {
+  switch (t) {
+    case 'pen': return '✎';
+    case 'highlighter': return '🖍';
+    case 'arrow': return '↗';
+    case 'rect': return '▭';
+    case 'circle': return '◯';
+    case 'text': return 'T';
+  }
+}
+
+function renderOp(ctx: CanvasRenderingContext2D, op: AnnotatorOp): void {
+  ctx.save();
+  ctx.lineCap = 'round';
+  ctx.lineJoin = 'round';
+  ctx.strokeStyle = op.color;
+  ctx.fillStyle = op.color;
+  ctx.lineWidth = op.width;
+
+  switch (op.tool) {
+    case 'pen': {
+      const pts = op.points;
+      if (!pts || pts.length < 1) break;
+      ctx.beginPath();
+      ctx.moveTo(pts[0]!.x, pts[0]!.y);
+      for (let i = 1; i < pts.length; i++) {
+        ctx.lineTo(pts[i]!.x, pts[i]!.y);
+      }
+      ctx.stroke();
+      break;
+    }
+    case 'highlighter': {
+      const pts = op.points;
+      if (!pts || pts.length < 1) break;
+      ctx.globalAlpha = 0.35;
+      ctx.lineWidth = op.width * 4;
+      ctx.beginPath();
+      ctx.moveTo(pts[0]!.x, pts[0]!.y);
+      for (let i = 1; i < pts.length; i++) {
+        ctx.lineTo(pts[i]!.x, pts[i]!.y);
+      }
+      ctx.stroke();
+      break;
+    }
+    case 'rect': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      ctx.strokeRect(
+        Math.min(from.x, to.x),
+        Math.min(from.y, to.y),
+        Math.abs(to.x - from.x),
+        Math.abs(to.y - from.y),
+      );
+      break;
+    }
+    case 'circle': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      const cx = (from.x + to.x) / 2;
+      const cy = (from.y + to.y) / 2;
+      const rx = Math.abs(to.x - from.x) / 2;
+      const ry = Math.abs(to.y - from.y) / 2;
+      ctx.beginPath();
+      ctx.ellipse(cx, cy, rx, ry, 0, 0, Math.PI * 2);
+      ctx.stroke();
+      break;
+    }
+    case 'arrow': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      ctx.beginPath();
+      ctx.moveTo(from.x, from.y);
+      ctx.lineTo(to.x, to.y);
+      ctx.stroke();
+      const angle = Math.atan2(to.y - from.y, to.x - from.x);
+      const head = Math.max(12, op.width * 3);
+      ctx.beginPath();
+      ctx.moveTo(to.x, to.y);
+      ctx.lineTo(
+        to.x - head * Math.cos(angle - Math.PI / 6),
+        to.y - head * Math.sin(angle - Math.PI / 6),
+      );
+      ctx.moveTo(to.x, to.y);
+      ctx.lineTo(
+        to.x - head * Math.cos(angle + Math.PI / 6),
+        to.y - head * Math.sin(angle + Math.PI / 6),
+      );
+      ctx.stroke();
+      break;
+    }
+    case 'text': {
+      const { at, text } = op;
+      if (!at || !text) break;
+      const fontSize = Math.max(14, op.width * 6);
+      ctx.font = '600 ' + fontSize + 'px Inter, system-ui, sans-serif';
+      ctx.textBaseline = 'top';
+      ctx.fillText(text, at.x, at.y);
+      break;
+    }
+  }
+
+  ctx.restore();
+}

apps/desktop/src/components/InCallPanel.tsx

@@ -1542,8 +1542,8 @@ function FullscreenCall({
 function StripToggleIcon({ hidden }: { hidden: boolean }) {
   return (
     <svg
-      width="18"
-      height="18"
+      width="14"
+      height="14"
       viewBox="0 0 24 24"
       fill="none"
       stroke="currentColor"

apps/desktop/src/components/MentionAutocomplete.tsx

@@ -1,8 +1,11 @@
 import type { ConversationSummary } from '@chat-app/shared/chat';
 import { useEffect, useState } from 'react';
 
+import { useNickname } from '../lib/friendNicknames';
 import { Avatar } from './Avatar';
 
+type Member = ConversationSummary['members'][number];
+
 interface Props {
   members: ConversationSummary['members'];
   query: string;
@@ -63,37 +66,58 @@ export function MentionAutocomplete({ members, query, excludeUserId, onSelect, o
       aria-label="Mitglieder"
       className="absolute bottom-full left-0 right-0 z-20 mb-2 max-h-64 overflow-y-auto rounded-xl border border-line bg-surface-2 p-1 shadow-xl dark:bg-[#2b2d31]"
     >
-      {matches.map((m, idx) => {
-        const name = m.profile?.displayName ?? m.profile?.username ?? '?';
-        const handle = m.profile?.username ?? '';
-        const isActive = idx === active;
-        return (
-          <button
-            key={m.userId}
-            type="button"
-            role="option"
-            aria-selected={isActive}
-            onMouseEnter={() => setActive(idx)}
-            onClick={() => {
-              if (m.profile?.username) onSelect(m.profile.username);
-            }}
-            className={
-              'flex w-full cursor-pointer items-center gap-2 rounded-lg px-2 py-1.5 text-left text-sm transition ' +
-              (isActive
-                ? 'bg-accent/20 text-fg'
-                : 'text-fg-muted hover:bg-surface-3 dark:hover:bg-[#383a40]')
-            }
-          >
-            <Avatar
-              displayName={name}
-              url={m.profile?.avatarUrl ?? null}
-              className="h-6 w-6 text-[10px]"
-            />
-            <span className="min-w-0 flex-1 truncate text-fg">{name}</span>
-            <span className="shrink-0 text-[10px] text-fg-muted">@{handle}</span>
-          </button>
-        );
-      })}
+      {matches.map((m, idx) => (
+        <MemberRow
+          key={m.userId}
+          member={m}
+          isActive={idx === active}
+          onActivate={() => setActive(idx)}
+          onSelect={onSelect}
+        />
+      ))}
     </div>
   );
 }
+
+// Extracted per-row component so we can call `useNickname` once per member
+// at the top of THIS component (hooks can't run inside .map callbacks).
+function MemberRow({
+  member,
+  isActive,
+  onActivate,
+  onSelect,
+}: {
+  member: Member;
+  isActive: boolean;
+  onActivate: () => void;
+  onSelect: (username: string) => void;
+}) {
+  const fallback = member.profile?.displayName ?? member.profile?.username ?? '?';
+  const name = useNickname(member.userId, fallback);
+  const handle = member.profile?.username ?? '';
+  return (
+    <button
+      type="button"
+      role="option"
+      aria-selected={isActive}
+      onMouseEnter={onActivate}
+      onClick={() => {
+        if (member.profile?.username) onSelect(member.profile.username);
+      }}
+      className={
+        'flex w-full cursor-pointer items-center gap-2 rounded-lg px-2 py-1.5 text-left text-sm transition ' +
+        (isActive
+          ? 'bg-accent/20 text-fg'
+          : 'text-fg-muted hover:bg-surface-3 dark:hover:bg-[#383a40]')
+      }
+    >
+      <Avatar
+        displayName={name}
+        url={member.profile?.avatarUrl ?? null}
+        className="h-6 w-6 text-[10px]"
+      />
+      <span className="min-w-0 flex-1 truncate text-fg">{name}</span>
+      <span className="shrink-0 text-[10px] text-fg-muted">@{handle}</span>
+    </button>
+  );
+}

apps/desktop/src/components/MessageBubble.tsx

@@ -5,11 +5,12 @@ import {
   softDeleteMessage,
 } from '@chat-app/shared/chat';
 import { extractErrorCode } from '@chat-app/shared/i18n';
-import { useCallback, useEffect, useRef, useState } from 'react';
+import { memo, useCallback, useEffect, useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
 import { useTranslation } from 'react-i18next';
 
 import { useAuth } from '../context/AuthContext';
+import { useNickname } from '../lib/friendNicknames';
 import { ensureInstallId } from '../lib/installId';
 import { supabase } from '../lib/supabase';
 import { cachedUserKey } from '../lib/userIdentity';
@@ -30,6 +31,7 @@ import {
   PencilIcon,
   PhoneIcon,
   PhoneOffIcon,
+  PinIcon,
   ReplyIcon,
   SmileIcon,
   SpinnerIcon,
@@ -58,8 +60,17 @@ interface Props {
   senderAvatarUrl?: string | null | undefined;
   conversationId: string;
   reactions: AggregatedReaction[];
-  onToggleReaction: (emoji: string) => Promise<void>;
-  onVotePoll?: (emoji: string, optionEmojis: string[]) => Promise<void>;
+  /**
+   * Toggle a reaction on this message. Receives the message id so the parent
+   * can pass a stable handler reference across every row (lets `React.memo`
+   * actually skip re-renders triggered by composer keystrokes / typing pings).
+   */
+  onToggleReaction: (messageId: string, emoji: string) => Promise<void>;
+  /**
+   * Cast/clear an exclusive poll vote. Receives the message id for the same
+   * reason as `onToggleReaction`.
+   */
+  onVotePoll?: (messageId: string, emoji: string, optionEmojis: string[]) => Promise<void>;
   showSeen?: boolean;
   /** Delivery state for own messages: 'sent' / 'delivered' / 'read'. */
   deliveryState?: 'sent' | 'delivered' | 'read';
@@ -75,9 +86,13 @@ interface Props {
   onAvatarClick?: (userId: string, ev: React.MouseEvent) => void;
   /** Highlighted state — set briefly after a jump. */
   highlighted?: boolean;
+  /** True iff this message is currently pinned (parent maintains the set). */
+  isPinned?: boolean;
+  /** Right-click menu → toggle pin/unpin for this message id. */
+  onTogglePin?: (messageId: string) => void;
 }
 
-export function MessageBubble({
+function MessageBubbleInner({
   message,
   mine,
   groupedWithPrev,
@@ -96,10 +111,18 @@ export function MessageBubble({
   onForward,
   onAvatarClick,
   highlighted = false,
+  isPinned = false,
+  onTogglePin,
 }: Props) {
   const { t } = useTranslation(['app']);
   const { session } = useAuth();
 
+  // Per-viewer nickname override for the message sender. Fallback chain
+  // keeps the existing behavior when no nickname is set. Skipped for the
+  // quoted-sender snippet — that's a different user.
+  const senderName = useNickname(message.senderId, senderDisplayName ?? '');
+  const resolvedSenderDisplayName = senderName.length > 0 ? senderName : null;
+
   const parsed = parseMessagePayload(message.plaintext);
   const initialText = parsed.kind === 'text' ? parsed.text : '';
   const initialAttachments = parsed.kind === 'text' ? parsed.attachments : [];
@@ -243,12 +266,12 @@ export function MessageBubble({
     async (emoji: string) => {
       setPickerOpen(false);
       try {
-        await onToggleReaction(emoji);
+        await onToggleReaction(message.id, emoji);
       } catch (err: unknown) {
         console.error('toggleReaction failed', err);
       }
     },
-    [onToggleReaction],
+    [onToggleReaction, message.id],
   );
 
   const copyableText =
@@ -281,7 +304,7 @@ export function MessageBubble({
         <AvatarSlot
           show={isLastOfRun}
           url={senderAvatarUrl ?? null}
-          displayName={senderDisplayName ?? null}
+          displayName={resolvedSenderDisplayName}
           {...(onAvatarClick
             ? { onClick: (ev: React.MouseEvent) => onAvatarClick(message.senderId, ev) }
             : {})}
@@ -299,7 +322,7 @@ export function MessageBubble({
         parsed={parsed}
         mine={mine}
         time={time}
-        senderDisplayName={senderDisplayName ?? null}
+        senderDisplayName={resolvedSenderDisplayName}
       />
     );
   }
@@ -315,7 +338,7 @@ export function MessageBubble({
       <AvatarSlot
         show={isLastOfRun}
         url={senderAvatarUrl ?? null}
-        displayName={senderDisplayName ?? null}
+        displayName={resolvedSenderDisplayName}
         {...(onAvatarClick
           ? { onClick: (ev: React.MouseEvent) => onAvatarClick(message.senderId, ev) }
           : {})}
@@ -428,6 +451,84 @@ export function MessageBubble({
                   defaultValue: 'Nachricht nicht lesbar',
                 })}
               </span>
+            ) : parsed.kind === 'game' ? (
+              <div className="flex items-center gap-3 rounded-2xl border border-accent/30 bg-accent/5 px-4 py-3">
+                <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-lg bg-accent/20 text-accent">
+                  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2}
+                       strokeLinecap="round" strokeLinejoin="round" className="h-5 w-5">
+                    <rect x="3" y="6" width="18" height="12" rx="3" />
+                    <path d="M8 12h4M10 10v4M16 11v.01M16 14v.01" />
+                  </svg>
+                </div>
+                <div className="min-w-0 flex-1">
+                  <div className="text-sm font-semibold text-fg">{parsed.gameType === 'c4' ? 'Vier-Gewinnt' : 'Tic-Tac-Toe'}</div>
+                  <div className="text-xs text-fg-muted">Gemeinsam spielen</div>
+                </div>
+                <button
+                  type="button"
+                  onClick={() => {
+                    window.dispatchEvent(
+                      new CustomEvent('chatapp:open-game', { detail: { id: parsed.gameId } }),
+                    );
+                  }}
+                  disabled={!parsed.gameId}
+                  className="cursor-pointer rounded-md bg-accent px-3 py-1.5 text-xs font-semibold text-accent-fg transition hover:bg-accent/90 disabled:cursor-not-allowed disabled:opacity-50"
+                >
+                  Spielen
+                </button>
+              </div>
+            ) : parsed.kind === 'watch_together' ? (
+              <div className="flex items-center gap-3 rounded-2xl border border-accent/30 bg-accent/5 px-4 py-3">
+                <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-lg bg-accent/20 text-accent">
+                  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2}
+                       strokeLinecap="round" strokeLinejoin="round" className="h-5 w-5">
+                    <rect x="3" y="4" width="18" height="14" rx="2" />
+                    <path d="M10 9l5 3-5 3V9z" fill="currentColor" stroke="none" />
+                  </svg>
+                </div>
+                <div className="min-w-0 flex-1">
+                  <div className="text-sm font-semibold text-fg">Watch Together</div>
+                  <div className="text-xs text-fg-muted">YouTube synchronisiert ansehen</div>
+                </div>
+                <button
+                  type="button"
+                  onClick={() => {
+                    window.dispatchEvent(
+                      new CustomEvent('chatapp:open-watch-together', { detail: { id: parsed.sessionId } }),
+                    );
+                  }}
+                  disabled={!parsed.sessionId}
+                  className="cursor-pointer rounded-md bg-accent px-3 py-1.5 text-xs font-semibold text-accent-fg transition hover:bg-accent/90 disabled:cursor-not-allowed disabled:opacity-50"
+                >
+                  Beitreten
+                </button>
+              </div>
+            ) : parsed.kind === 'whiteboard' ? (
+              <div className="flex items-center gap-3 rounded-2xl border border-accent/30 bg-accent/5 px-4 py-3">
+                <div className="flex h-10 w-10 shrink-0 items-center justify-center rounded-lg bg-accent/20 text-accent">
+                  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2}
+                       strokeLinecap="round" strokeLinejoin="round" className="h-5 w-5">
+                    <rect x="3" y="4" width="18" height="13" rx="2" />
+                    <path d="M8 21h8M12 17v4" />
+                  </svg>
+                </div>
+                <div className="min-w-0 flex-1">
+                  <div className="text-sm font-semibold text-fg">Whiteboard</div>
+                  <div className="text-xs text-fg-muted">Gemeinsames Zeichnen</div>
+                </div>
+                <button
+                  type="button"
+                  onClick={() => {
+                    window.dispatchEvent(
+                      new CustomEvent('chatapp:open-whiteboard', { detail: { id: parsed.whiteboardId } }),
+                    );
+                  }}
+                  disabled={!parsed.whiteboardId}
+                  className="cursor-pointer rounded-md bg-accent px-3 py-1.5 text-xs font-semibold text-accent-fg transition hover:bg-accent/90 disabled:cursor-not-allowed disabled:opacity-50"
+                >
+                  Öffnen
+                </button>
+              </div>
             ) : parsed.kind === 'poll' ? (
               <PollCard
                 question={parsed.question}
@@ -435,7 +536,9 @@ export function MessageBubble({
                 reactions={reactions}
                 mine={mine}
                 onVote={(emoji) =>
-                  onVotePoll ? onVotePoll(emoji, pollOptionEmojis) : onToggleReaction(emoji)
+                  onVotePoll
+                    ? onVotePoll(message.id, emoji, pollOptionEmojis)
+                    : onToggleReaction(message.id, emoji)
                 }
               />
             ) : (
@@ -451,7 +554,7 @@ export function MessageBubble({
                     return <AttachmentAudio key={a.id} handle={a} />;
                   }
                   if (a.mimeType.startsWith('image/')) {
-                    return <AttachmentImage key={a.id} handle={a} />;
+                    return <AttachmentImage key={a.id} handle={a} mine={mine} />;
                   }
                   if (a.mimeType.startsWith('video/')) {
                     return <AttachmentVideo key={a.id} handle={a} />;
@@ -501,7 +604,7 @@ export function MessageBubble({
               <button
                 key={r.emoji + ':' + r.count}
                 type="button"
-                onClick={() => void onToggleReaction(r.emoji)}
+                onClick={() => void onToggleReaction(message.id, r.emoji)}
                 className={
                   'inline-flex origin-bottom animate-reaction-pop cursor-pointer items-center gap-1 rounded-full border px-2 py-0.5 text-xs transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
                   (r.mine
@@ -635,6 +738,15 @@ export function MessageBubble({
               setContextMenu(null);
               void handleDelete();
             }}
+            isPinned={isPinned}
+            {...(onTogglePin
+              ? {
+                  onTogglePin: () => {
+                    setContextMenu(null);
+                    onTogglePin(message.id);
+                  },
+                }
+              : {})}
           />
         )}
       </div>
@@ -642,6 +754,14 @@ export function MessageBubble({
   );
 }
 
+/**
+ * Memoized export. Skips re-rendering when none of its props' shallow
+ * references change — i.e. when the parent re-renders due to composer
+ * keystrokes, typing-indicator updates, presence pings, etc. Relies on
+ * the parent passing stable callback refs (see `ConversationPage`).
+ */
+export const MessageBubble = memo(MessageBubbleInner);
+
 function PollCard({
   question,
   options,
@@ -732,6 +852,8 @@ function MessageContextMenu({
   onEdit,
   onCopy,
   onDelete,
+  isPinned,
+  onTogglePin,
 }: {
   x: number;
   y: number;
@@ -746,6 +868,8 @@ function MessageContextMenu({
   onEdit: () => void;
   onCopy: () => void;
   onDelete: () => void;
+  isPinned?: boolean;
+  onTogglePin?: () => void;
 }) {
   useEffect(() => {
     function onKey(e: KeyboardEvent) {
@@ -812,6 +936,13 @@ function MessageContextMenu({
           tone="danger"
         />
       )}
+      {onTogglePin && (
+        <MenuItem
+          label={isPinned ? 'Anheftung entfernen' : 'Anpinnen'}
+          icon={<PinIcon className="h-4 w-4" />}
+          onClick={onTogglePin}
+        />
+      )}
     </div>,
     document.body,
   );

apps/desktop/src/components/NicknameDialog.tsx

@@ -0,0 +1,81 @@
+import { useEffect, useRef, useState } from 'react';
+
+import { getNickname, setNickname } from '../lib/friendNicknames';
+
+interface Props {
+  open: boolean;
+  userId: string;
+  displayName: string;
+  onClose: () => void;
+}
+
+export function NicknameDialog({ open, userId, displayName, onClose }: Props) {
+  const [value, setValue] = useState('');
+  const inputRef = useRef<HTMLInputElement | null>(null);
+
+  useEffect(() => {
+    if (!open) return;
+    setValue(getNickname(userId) ?? '');
+    setTimeout(() => inputRef.current?.focus(), 0);
+  }, [open, userId]);
+
+  useEffect(() => {
+    if (!open) return;
+    const onKey = (e: KeyboardEvent) => { if (e.key === 'Escape') onClose(); };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [open, onClose]);
+
+  if (!open) return null;
+
+  const submit = (): void => {
+    setNickname(userId, value);
+    onClose();
+  };
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label="Spitzname setzen"
+      className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4"
+      onClick={onClose}
+    >
+      <div
+        onClick={(e) => e.stopPropagation()}
+        className="w-full max-w-sm rounded-2xl border border-line bg-surface-2 p-5 shadow-xl"
+      >
+        <h3 className="font-display text-base font-semibold text-fg">Spitzname für {displayName}</h3>
+        <p className="mt-1 text-xs text-fg-muted">
+          Nur du siehst diesen Namen. Leer lassen = den richtigen Namen verwenden.
+        </p>
+        <input
+          ref={inputRef}
+          type="text"
+          value={value}
+          onChange={(e) => setValue(e.target.value)}
+          onKeyDown={(e) => { if (e.key === 'Enter') submit(); }}
+          maxLength={32}
+          placeholder={displayName}
+          className="mt-4 w-full rounded-lg border border-line bg-surface-3 px-3 py-2 text-sm text-fg placeholder-fg-muted focus:border-accent focus:outline-none focus:ring-2 focus:ring-accent/30"
+        />
+        <div className="mt-4 flex justify-end gap-2">
+          <button
+            type="button"
+            onClick={onClose}
+            className="cursor-pointer rounded-md border border-line bg-surface-3 px-3 py-2 text-sm text-fg hover:bg-surface-2"
+          >
+            Abbrechen
+          </button>
+          <button
+            type="button"
+            onClick={submit}
+            className="cursor-pointer rounded-md bg-accent px-3 py-2 text-sm font-semibold text-accent-fg hover:brightness-110"
+          >
+            Speichern
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

apps/desktop/src/components/PinnedMessagesPanel.tsx

@@ -0,0 +1,68 @@
+import type { PinnedMessage } from '@chat-app/shared/chat';
+
+import { PinIcon, XIcon } from './icons';
+
+interface Props {
+  open: boolean;
+  pins: PinnedMessage[];
+  onClose: () => void;
+  onJump: (messageId: string) => void;
+  onUnpin: (messageId: string) => void;
+  // Optional preview-renderer: parent resolves messageId → short text/snippet
+  // since the panel itself doesn't decrypt. If absent, the panel just shows
+  // the message-id stub.
+  renderPreview?: (messageId: string) => React.ReactNode;
+}
+
+export function PinnedMessagesPanel({ open, pins, onClose, onJump, onUnpin, renderPreview }: Props) {
+  if (!open) return null;
+  return (
+    <aside
+      role="complementary"
+      aria-label="Angepinnte Nachrichten"
+      className="absolute right-0 top-0 z-30 flex h-full w-80 flex-col border-l border-line bg-surface-2 shadow-xl"
+    >
+      <header className="flex items-center justify-between border-b border-line px-4 py-3">
+        <div className="flex items-center gap-2">
+          <PinIcon className="h-4 w-4 text-accent" />
+          <h3 className="text-sm font-semibold text-fg">Angepinnt · {pins.length}</h3>
+        </div>
+        <button
+          type="button"
+          onClick={onClose}
+          aria-label="Schließen"
+          className="flex h-7 w-7 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-4 w-4" />
+        </button>
+      </header>
+      {pins.length === 0 ? (
+        <p className="p-6 text-center text-xs text-fg-muted">Noch nichts angepinnt.</p>
+      ) : (
+        <ul className="flex-1 overflow-y-auto">
+          {pins.map((p) => (
+            <li key={p.messageId} className="border-b border-line/60 px-4 py-3">
+              <button
+                type="button"
+                onClick={() => onJump(p.messageId)}
+                className="block w-full cursor-pointer text-left text-sm text-fg hover:text-accent"
+              >
+                {renderPreview ? renderPreview(p.messageId) : <span className="font-mono text-xs">{p.messageId.slice(0, 8)}</span>}
+              </button>
+              <div className="mt-1 flex items-center justify-between text-[11px] text-fg-muted">
+                <time dateTime={p.pinnedAt}>{new Date(p.pinnedAt).toLocaleString()}</time>
+                <button
+                  type="button"
+                  onClick={() => onUnpin(p.messageId)}
+                  className="cursor-pointer text-rose-400 hover:underline"
+                >
+                  Anheftung entfernen
+                </button>
+              </div>
+            </li>
+          ))}
+        </ul>
+      )}
+    </aside>
+  );
+}

apps/desktop/src/components/PinnedMessagesPill.tsx

@@ -0,0 +1,23 @@
+import { PinIcon } from './icons';
+
+interface Props {
+  count: number;
+  onClick: () => void;
+}
+
+// Compact chip rendered in the conv header that opens the pinned panel.
+// Renders nothing when count is 0 so a fresh conv shows no clutter.
+export function PinnedMessagesPill({ count, onClick }: Props) {
+  if (count === 0) return null;
+  return (
+    <button
+      type="button"
+      onClick={onClick}
+      className="inline-flex h-7 cursor-pointer items-center gap-1.5 rounded-full border border-line bg-surface-3 px-2.5 text-xs font-medium text-fg-muted transition hover:bg-surface-2 hover:text-fg focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
+      title="Angepinnte Nachrichten anzeigen"
+    >
+      <PinIcon className="h-3 w-3 text-accent" />
+      <span>{count} angepinnt</span>
+    </button>
+  );
+}

apps/desktop/src/components/RemoteRevokedScreen.tsx

@@ -0,0 +1,41 @@
+import { useTranslation } from 'react-i18next';
+
+import { useAuth } from '../context/AuthContext';
+
+export function RemoteRevokedScreen() {
+  const { t } = useTranslation();
+  const { revokedRemotely, acknowledgeRevocation } = useAuth();
+
+  if (!revokedRemotely) return null;
+
+  return (
+    <div
+      role="alertdialog"
+      aria-modal="true"
+      aria-labelledby="remote-revoked-title"
+      className="fixed inset-0 z-[1000] flex items-center justify-center bg-ink-950/95 p-6"
+    >
+      <div className="max-w-sm rounded-2xl border border-line bg-surface-2 p-6 text-center shadow-xl">
+        <h2
+          id="remote-revoked-title"
+          className="mb-2 font-display text-xl font-semibold text-fg"
+        >
+          {t('app:auth.revoked_title', { defaultValue: 'Du wurdest remote abgemeldet' })}
+        </h2>
+        <p className="mb-5 text-sm text-fg-muted">
+          {t('app:auth.revoked_body', {
+            defaultValue:
+              'Ein anderes deiner Geräte hat diesen Login beendet. Aus Sicherheitsgründen wurden alle lokalen Daten gelöscht.',
+          })}
+        </p>
+        <button
+          type="button"
+          onClick={acknowledgeRevocation}
+          className="inline-flex cursor-pointer items-center justify-center rounded-lg bg-accent px-4 py-2 text-sm font-semibold text-accent-fg transition hover:brightness-110 focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
+        >
+          {t('app:auth.revoked_acknowledge', { defaultValue: 'Verstanden' })}
+        </button>
+      </div>
+    </div>
+  );
+}

apps/desktop/src/components/SecurityCenter.tsx

@@ -1,5 +1,12 @@
 import { useState } from 'react';
 
+import {
+  type AutoLockMinutes,
+  getAutoLockMinutes,
+  notifyAutoLockChanged,
+  setAutoLockMinutes,
+} from '../lib/autoLockSettings';
+import { isWipeOnCloseEnabled, setWipeOnClose } from '../lib/memoryWipeSettings';
 import {
   changePin,
   type LegacyMigrationReport,
@@ -19,6 +26,8 @@ export function SecurityCenter({ userId }: Props) {
   const [msg, setMsg] = useState<string | null>(null);
   const [recovery, setRecovery] = useState<string | null>(null);
   const [migration, setMigration] = useState<LegacyMigrationReport | null>(null);
+  const [wipeOnClose, setWipeOnCloseState] = useState<boolean>(() => isWipeOnCloseEnabled());
+  const [autoLockMinutes, setAutoLockMinutesState] = useState<AutoLockMinutes>(() => getAutoLockMinutes());
 
   async function handleRetryMigration() {
     setBusy(true); setMsg(null); setMigration(null);
@@ -126,6 +135,60 @@ export function SecurityCenter({ userId }: Props) {
         )}
       </section>
 
+      <section>
+        <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-fg-muted">
+          Cache beim Schließen leeren
+        </h3>
+        <p className="mb-2 text-xs text-fg-muted">
+          Beim Beenden der App werden alle entschlüsselten Caches gelöscht. Beim nächsten Start
+          musst du wieder deine PIN eingeben. Empfohlen für gemeinsam genutzte Rechner.
+        </p>
+        <label className="inline-flex cursor-pointer items-center gap-2 text-sm">
+          <input
+            type="checkbox"
+            checked={wipeOnClose}
+            onChange={(e) => {
+              setWipeOnClose(e.target.checked);
+              setWipeOnCloseState(e.target.checked);
+            }}
+          />
+          <span>Aktivieren</span>
+        </label>
+      </section>
+
+      <section>
+        <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-fg-muted">
+          Auto-Lock nach Inaktivität
+        </h3>
+        <p className="mb-2 text-xs text-fg-muted">
+          Verlangt erneute PIN-Eingabe nach der gewählten Inaktivitätsdauer. Empfohlen für gemeinsam genutzte Rechner.
+        </p>
+        <div className="flex items-center justify-between gap-3">
+          <div>
+            <div className="text-sm font-medium text-fg">Automatisch sperren</div>
+            <div className="text-xs text-fg-muted">
+              Verlangt erneute PIN-Eingabe nach X Minuten Inaktivität.
+            </div>
+          </div>
+          <select
+            value={autoLockMinutes}
+            onChange={(e) => {
+              const next = Number(e.target.value) as AutoLockMinutes;
+              setAutoLockMinutes(next);
+              notifyAutoLockChanged(next);
+              setAutoLockMinutesState(next);
+            }}
+            className="cursor-pointer rounded-md border border-line bg-surface-2 px-3 py-1.5 text-sm text-fg focus:border-accent focus:outline-none focus:ring-1 focus:ring-accent/40"
+          >
+            <option value={0}>Aus</option>
+            <option value={5}>5 min</option>
+            <option value={15}>15 min</option>
+            <option value={30}>30 min</option>
+            <option value={60}>60 min</option>
+          </select>
+        </div>
+      </section>
+
       <section>
         <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-rose-400">Identität zurücksetzen</h3>
         <p className="mb-2 text-xs text-fg-muted">Erstellt einen neuen Schlüssel. Alle alten Chats werden unlesbar.</p>

apps/desktop/src/components/Sidebar.tsx

@@ -17,7 +17,7 @@ import {
 interface NavItem {
   to: string;
   labelKey: string;
-  icon: (props: React.SVGProps<SVGSVGElement>) => React.JSX.Element;
+  icon: React.ComponentType<React.ComponentPropsWithoutRef<'svg'>>;
   badge?: 'friends' | 'chats';
 }
 
@@ -95,7 +95,7 @@ export function Sidebar() {
 interface RailNavLinkProps {
   to: string;
   label: string;
-  icon: (props: React.SVGProps<SVGSVGElement>) => React.JSX.Element;
+  icon: React.ComponentType<React.ComponentPropsWithoutRef<'svg'>>;
   badge?: number;
 }
 
@@ -135,7 +135,7 @@ function RailNavLink({ to, label, icon: Icon, badge = 0 }: RailNavLinkProps) {
 interface RailIconButtonProps {
   label: string;
   onClick: () => void;
-  icon: (props: React.SVGProps<SVGSVGElement>) => React.JSX.Element;
+  icon: React.ComponentType<React.ComponentPropsWithoutRef<'svg'>>;
   tone?: 'default' | 'danger';
 }
 

apps/desktop/src/components/SoundboardManagerDialog.tsx

@@ -1,6 +1,7 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 
+import { deleteSound as deleteRemoteSound } from '@chat-app/shared/chat';
 import { getPttSettings } from '../lib/pttSettings';
 import { codeToShortcut } from '../lib/globalShortcut';
 import { invalidate as invalidateSoundCache, preload } from '../lib/soundboardPlayback';
@@ -15,6 +16,8 @@ import {
   subscribeSoundboardChanges,
   updateSound,
 } from '../lib/soundboardStorage';
+import { supabase } from '../lib/supabase';
+import { useSoundboardSync, type SyncBadge } from '../hooks/useSoundboardSync';
 import { Modal } from './Modal';
 import {
   AlertIcon,
@@ -46,6 +49,7 @@ export function SoundboardManagerDialog({ open, onClose }: Props) {
   const [busyId, setBusyId] = useState<string | null>(null);
   const [error, setError] = useState<string | null>(null);
   const [previewingId, setPreviewingId] = useState<string | null>(null);
+  const { badges } = useSoundboardSync();
 
   const refresh = useCallback(async () => {
     setLoading(true);
@@ -167,6 +171,11 @@ export function SoundboardManagerDialog({ open, onClose }: Props) {
     }
     setBusyId(id);
     try {
+      try {
+        await deleteRemoteSound(supabase, id);
+      } catch (err) {
+        console.warn('remote sound delete failed (local delete proceeds)', err);
+      }
       await deleteSound(id);
       invalidateSoundCache(id);
       if (previewingId === id) stopPreview();
@@ -301,6 +310,7 @@ export function SoundboardManagerDialog({ open, onClose }: Props) {
                   entriesTotal={entries}
                   busyId={busyId}
                   previewingId={previewingId}
+                  badges={badges}
                   onPatch={handlePatch}
                   onDelete={handleDelete}
                   onPreview={handlePreview}
@@ -323,6 +333,7 @@ interface GroupProps {
   entriesTotal: SoundboardEntry[];
   busyId: string | null;
   previewingId: string | null;
+  badges: Map<string, SyncBadge>;
   onPatch: (id: string, patch: Parameters<typeof updateSound>[1]) => Promise<void>;
   onDelete: (id: string) => Promise<void>;
   onPreview: (entry: SoundboardEntry) => Promise<void>;
@@ -335,6 +346,7 @@ function SoundboardCategoryGroup({
   entriesTotal,
   busyId,
   previewingId,
+  badges,
   onPatch,
   onDelete,
   onPreview,
@@ -370,6 +382,7 @@ function SoundboardCategoryGroup({
               isLast={idx === entries.length - 1}
               busy={busyId === entry.id}
               previewing={previewingId === entry.id}
+              badge={badges.get(entry.id)}
               onPatch={onPatch}
               onDelete={onDelete}
               onPreview={onPreview}
@@ -392,6 +405,7 @@ interface RowProps {
   isLast: boolean;
   busy: boolean;
   previewing: boolean;
+  badge: SyncBadge | undefined;
   onPatch: (id: string, patch: Parameters<typeof updateSound>[1]) => Promise<void>;
   onDelete: (id: string) => Promise<void>;
   onPreview: (entry: SoundboardEntry) => Promise<void>;
@@ -406,6 +420,7 @@ function SoundboardRow({
   isLast,
   busy,
   previewing,
+  badge,
   onPatch,
   onDelete,
   onPreview,
@@ -503,6 +518,13 @@ function SoundboardRow({
         )}
         <p className="text-[10px] text-fg-muted">
           {(entry.size / BYTES_PER_MB).toFixed(2)} MB · {entry.mime}
+          <span
+            title={badgeTitle(badge)}
+            aria-label={badgeTitle(badge)}
+            className="ml-2 inline-flex items-center text-[10px] font-medium text-fg-muted"
+          >
+            {badgeGlyph(badge)}
+          </span>
         </p>
       </div>
 
@@ -623,3 +645,25 @@ function SoundboardRow({
     </li>
   );
 }
+
+// ---------------------------------------------------------------------------
+
+function badgeGlyph(b: SyncBadge | undefined): string {
+  switch (b) {
+    case 'uploading': return '↑';
+    case 'downloading': return '↓';
+    case 'error': return '⚠';
+    case 'synced':
+    default: return '☁';
+  }
+}
+
+function badgeTitle(b: SyncBadge | undefined): string {
+  switch (b) {
+    case 'uploading': return 'Hochladen…';
+    case 'downloading': return 'Wird heruntergeladen…';
+    case 'error': return 'Synchronisationsfehler';
+    case 'synced':
+    default: return 'Synchronisiert';
+  }
+}

apps/desktop/src/components/TicTacToeBoard.tsx

@@ -0,0 +1,53 @@
+import { type Cell, tttWinningLine } from '@chat-app/shared/chat';
+
+interface Props {
+  board: Cell[];
+  myPlayerIdx: 0 | 1 | null;
+  disabled: boolean;
+  onMove: (cell: number) => void;
+}
+
+const MARK = ['×', '○'] as const;
+
+export function TicTacToeBoard({ board, myPlayerIdx, disabled, onMove }: Props) {
+  const winLine = tttWinningLine(board);
+  const winSet = new Set<number>(winLine ?? []);
+
+  return (
+    <div
+      className="mx-auto grid w-full max-w-md grid-cols-3 gap-2 p-4"
+      style={{ aspectRatio: '1 / 1' }}
+      role="grid"
+      aria-label="Tic-Tac-Toe"
+    >
+      {board.map((cell, i) => {
+        const filled = cell !== null;
+        const inWin = winSet.has(i);
+        const canClick = !disabled && !filled && myPlayerIdx !== null;
+        return (
+          <button
+            key={i}
+            type="button"
+            onClick={() => canClick && onMove(i)}
+            disabled={!canClick}
+            aria-label={'Feld ' + (i + 1) + (filled ? ' belegt' : ' frei')}
+            className={
+              'flex aspect-square items-center justify-center rounded-xl border-2 text-5xl font-bold transition ' +
+              (inWin
+                ? 'border-emerald-400 bg-emerald-400/20 text-emerald-200'
+                : filled
+                  ? cell === 0
+                    ? 'border-rose-500/60 bg-rose-500/10 text-rose-300'
+                    : 'border-sky-500/60 bg-sky-500/10 text-sky-300'
+                  : canClick
+                    ? 'cursor-pointer border-line bg-surface-2 text-fg-muted hover:bg-surface-3 hover:text-fg'
+                    : 'cursor-not-allowed border-line bg-surface-2 text-fg-muted opacity-60')
+            }
+          >
+            {filled ? MARK[cell as 0 | 1] : ''}
+          </button>
+        );
+      })}
+    </div>
+  );
+}

apps/desktop/src/components/ViewOnceImage.tsx

@@ -0,0 +1,87 @@
+import { useState } from 'react';
+
+import { markAttachmentViewed } from '@chat-app/shared/chat';
+
+import { supabase } from '../lib/supabase';
+import { EyeOffIcon, LockIcon } from './icons';
+
+interface Props {
+  attachmentId: string;
+  /** Already-viewed timestamp from the DB row. Renders tombstone immediately. */
+  viewedAt: string | null;
+  /** True iff the local user is the sender — they don't burn the view. */
+  isSender: boolean;
+  /** Decrypted image source; only fetched/displayed inside the lightbox. */
+  src: string;
+}
+
+// Three states:
+//   1. viewedAt is null AND user is recipient → blurred lock card; tap opens
+//      fullscreen lightbox AND fires the mark-viewed RPC.
+//   2. viewedAt is set → tombstone "Angesehen am …".
+//   3. user is sender → normal image, tombstone update appears once recipient burns it.
+export function ViewOnceImage({ attachmentId, viewedAt, isSender, src }: Props) {
+  const [revealedAt, setRevealedAt] = useState<string | null>(viewedAt);
+  const [fullscreen, setFullscreen] = useState(false);
+
+  const burned = revealedAt !== null;
+
+  if (burned && !isSender) {
+    return (
+      <div className="flex h-32 w-48 items-center justify-center rounded-lg border border-dashed border-line bg-surface-3 text-xs text-fg-muted">
+        <EyeOffIcon className="mr-2 h-4 w-4" />
+        Angesehen am {new Date(revealedAt).toLocaleString()}
+      </div>
+    );
+  }
+
+  if (isSender) {
+    return (
+      <div className="relative">
+        <img src={src} alt="" className="max-h-72 rounded-lg" />
+        <span className="absolute left-2 top-2 inline-flex items-center gap-1 rounded-full bg-black/60 px-2 py-0.5 text-[10px] font-semibold text-white">
+          <EyeOffIcon className="h-3 w-3" /> Einmal ansehen
+        </span>
+        {burned && (
+          <span className="absolute right-2 bottom-2 rounded-full bg-emerald-500/80 px-2 py-0.5 text-[10px] font-semibold text-white">
+            Angesehen
+          </span>
+        )}
+      </div>
+    );
+  }
+
+  // Recipient, not yet viewed.
+  const handleOpen = async (): Promise<void> => {
+    try {
+      const res = await markAttachmentViewed(supabase, attachmentId);
+      if (res.viewedAt) setRevealedAt(res.viewedAt);
+    } catch (err) {
+      console.warn('mark-viewed failed', err);
+    }
+    setFullscreen(true);
+  };
+
+  return (
+    <>
+      <button
+        type="button"
+        onClick={() => void handleOpen()}
+        className="relative flex h-48 w-64 cursor-pointer flex-col items-center justify-center gap-2 rounded-lg border border-line bg-surface-3 text-fg-muted hover:border-accent/40"
+      >
+        <LockIcon className="h-6 w-6 text-accent" />
+        <span className="text-xs font-medium">Einmal ansehen — antippen</span>
+      </button>
+      {fullscreen && (
+        <div
+          role="dialog"
+          aria-modal="true"
+          className="fixed inset-0 z-50 flex items-center justify-center bg-black/90 p-6"
+          onClick={() => setFullscreen(false)}
+        >
+          <img src={src} alt="" className="max-h-full max-w-full rounded-lg" />
+        </div>
+      )}
+    </>
+  );
+}

apps/desktop/src/components/WatchTogetherModal.tsx

@@ -0,0 +1,260 @@
+import { useEffect, useRef, useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useAuth } from '../context/AuthContext';
+import { useWatchSession } from '../hooks/useWatchSession';
+import { XIcon } from './icons';
+
+interface YTPlayer {
+  playVideo: () => void;
+  pauseVideo: () => void;
+  seekTo: (seconds: number, allowSeekAhead: boolean) => void;
+  getCurrentTime: () => number;
+  getPlayerState: () => number;
+  destroy: () => void;
+}
+
+interface YTPlayerOptions {
+  width: string | number;
+  height: string | number;
+  videoId: string;
+  playerVars?: { autoplay?: 0 | 1; controls?: 0 | 1; modestbranding?: 0 | 1 };
+  events?: {
+    onReady?: (ev: { target: YTPlayer }) => void;
+    onStateChange?: (ev: { data: number; target: YTPlayer }) => void;
+  };
+}
+
+interface YTNamespace {
+  Player: new (elementId: string | HTMLElement, opts: YTPlayerOptions) => YTPlayer;
+  PlayerState: { UNSTARTED: -1; ENDED: 0; PLAYING: 1; PAUSED: 2; BUFFERING: 3; CUED: 5 };
+}
+
+declare global {
+  interface Window {
+    YT?: YTNamespace;
+    onYouTubeIframeAPIReady?: () => void;
+  }
+}
+
+const IFRAME_API_URL = 'https://www.youtube.com/iframe_api';
+let apiPromise: Promise<YTNamespace> | null = null;
+
+function loadIframeApi(): Promise<YTNamespace> {
+  if (apiPromise) return apiPromise;
+  apiPromise = new Promise((resolve, reject) => {
+    if (typeof window === 'undefined') {
+      reject(new Error('no window'));
+      return;
+    }
+    if (window.YT?.Player) {
+      resolve(window.YT);
+      return;
+    }
+    const prev = window.onYouTubeIframeAPIReady;
+    window.onYouTubeIframeAPIReady = () => {
+      try {
+        prev?.();
+      } catch {
+        /* ignore */
+      }
+      if (window.YT?.Player) resolve(window.YT);
+      else reject(new Error('YT namespace missing after ready'));
+    };
+    const existing = document.querySelector(
+      'script[src="' + IFRAME_API_URL + '"]',
+    );
+    if (existing) return;
+    const tag = document.createElement('script');
+    tag.src = IFRAME_API_URL;
+    tag.async = true;
+    document.head.appendChild(tag);
+  });
+  return apiPromise;
+}
+
+interface Props {
+  sessionId: string;
+  onClose: () => void;
+}
+
+const DRIFT_THRESHOLD_SECONDS = 2;
+
+export function WatchTogetherModal({ sessionId, onClose }: Props) {
+  const { t } = useTranslation();
+  const { session, pushState, endSession, error, loading } = useWatchSession(sessionId);
+  const { session: auth } = useAuth();
+  const mountRef = useRef<HTMLDivElement | null>(null);
+  const playerRef = useRef<YTPlayer | null>(null);
+  const [playerReady, setPlayerReady] = useState(false);
+  const ownerId = session?.ownerUserId ?? null;
+  const isOwner = !!auth?.user.id && auth.user.id === ownerId;
+  const ended = !!session?.endedAt;
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [onClose]);
+
+  useEffect(() => {
+    if (!session?.videoId || !mountRef.current) return;
+    if (playerRef.current) return;
+    let disposed = false;
+    void loadIframeApi().then((YT) => {
+      if (disposed || !mountRef.current) return;
+      playerRef.current = new YT.Player(mountRef.current, {
+        width: '100%',
+        height: '100%',
+        videoId: session.videoId,
+        playerVars: { autoplay: 1, controls: isOwner ? 1 : 0, modestbranding: 1 },
+        events: {
+          onReady: () => setPlayerReady(true),
+          onStateChange: (ev) => {
+            if (!isOwner) return;
+            const playing = ev.data === YT.PlayerState.PLAYING;
+            const pos = ev.target.getCurrentTime();
+            pushState({ playing, positionSeconds: pos, updatedAtMs: Date.now() });
+          },
+        },
+      });
+    }).catch((err) => {
+      console.error('YouTube IFrame API failed', err);
+    });
+    return () => {
+      disposed = true;
+      try {
+        playerRef.current?.destroy();
+      } catch {
+        /* ignore */
+      }
+      playerRef.current = null;
+    };
+  }, [session?.videoId, isOwner, pushState]);
+
+  useEffect(() => {
+    if (!isOwner || !playerReady) return;
+    const id = window.setInterval(() => {
+      const p = playerRef.current;
+      if (!p) return;
+      try {
+        const state = p.getPlayerState();
+        const playing = state === window.YT?.PlayerState.PLAYING;
+        pushState({
+          playing,
+          positionSeconds: p.getCurrentTime(),
+          updatedAtMs: Date.now(),
+        });
+      } catch {
+        /* ignore */
+      }
+    }, 1000);
+    return () => window.clearInterval(id);
+  }, [isOwner, playerReady, pushState]);
+
+  useEffect(() => {
+    if (isOwner || !playerReady || !session) return;
+    const p = playerRef.current;
+    if (!p) return;
+    const remoteAgeSec = Math.max(0, (Date.now() - session.currentState.updatedAtMs) / 1000);
+    const projectedRemote = session.currentState.playing
+      ? session.currentState.positionSeconds + remoteAgeSec
+      : session.currentState.positionSeconds;
+    let local = 0;
+    try {
+      local = p.getCurrentTime();
+    } catch {
+      return;
+    }
+    if (Math.abs(local - projectedRemote) > DRIFT_THRESHOLD_SECONDS) {
+      try {
+        p.seekTo(projectedRemote, true);
+      } catch {
+        /* ignore */
+      }
+    }
+    try {
+      const state = p.getPlayerState();
+      const localPlaying = state === window.YT?.PlayerState.PLAYING;
+      if (session.currentState.playing && !localPlaying) {
+        p.playVideo();
+      } else if (!session.currentState.playing && localPlaying) {
+        p.pauseVideo();
+      }
+    } catch {
+      /* ignore */
+    }
+  }, [isOwner, playerReady, session]);
+
+  const handleClose = async () => {
+    if (isOwner && !ended) {
+      try {
+        await endSession();
+      } catch (err) {
+        console.warn('endSession failed', err);
+      }
+    }
+    onClose();
+  };
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label={t('app:watch.title', { defaultValue: 'Watch Together' })}
+      className="fixed inset-0 z-[80] flex flex-col bg-black"
+    >
+      <header className="flex shrink-0 items-center justify-between border-b border-line/40 bg-surface-2 px-4 py-2">
+        <h2 className="font-display text-sm font-semibold text-fg">
+          {t('app:watch.title', { defaultValue: 'Watch Together' })}
+          {ended && (
+            <span className="ml-2 rounded-md bg-rose-500/15 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-rose-600 dark:text-rose-300">
+              {t('app:watch.ended', { defaultValue: 'Beendet' })}
+            </span>
+          )}
+        </h2>
+        <button
+          type="button"
+          onClick={() => void handleClose()}
+          aria-label={t('app:watch.close', { defaultValue: 'Schließen' })}
+          className="flex h-7 w-7 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </header>
+
+      <div className="flex min-h-0 flex-1 items-center justify-center overflow-hidden bg-black p-4">
+        {loading ? (
+          <p className="text-sm text-fg-muted">
+            {t('app:watch.loading', { defaultValue: 'Lädt…' })}
+          </p>
+        ) : error ? (
+          <p className="text-sm text-rose-400">{error}</p>
+        ) : !session ? (
+          <p className="text-sm text-fg-muted">
+            {t('app:watch.missing', { defaultValue: 'Session nicht gefunden.' })}
+          </p>
+        ) : (
+          <div className="aspect-video w-full max-w-5xl">
+            <div ref={mountRef} className="h-full w-full" />
+          </div>
+        )}
+      </div>
+
+      <footer className="flex shrink-0 items-center justify-between gap-3 border-t border-line/40 bg-surface-2 px-4 py-2 text-xs text-fg-muted">
+        <span>
+          {isOwner
+            ? t('app:watch.you_are_host', { defaultValue: 'Du steuerst die Wiedergabe.' })
+            : t('app:watch.you_are_guest', { defaultValue: 'Nur der Host kann steuern.' })}
+        </span>
+        <span>
+          {session?.currentState.playing
+            ? t('app:watch.playing', { defaultValue: '▶ Läuft' })
+            : t('app:watch.paused', { defaultValue: '⏸ Pause' })}
+        </span>
+      </footer>
+    </div>
+  );
+}

apps/desktop/src/components/WhiteboardCanvas.tsx

@@ -0,0 +1,142 @@
+import { useEffect, useRef, useState } from 'react';
+
+import type { WhiteboardStroke } from '@chat-app/shared/chat';
+
+export type WhiteboardTool = 'pen' | 'eraser';
+export type WhiteboardColor = '#000000' | '#ef4444' | '#3b82f6' | '#22c55e' | '#facc15' | '#a855f7';
+export type WhiteboardWidth = 2 | 4 | 8;
+
+export interface WhiteboardStrokePayload {
+  tool: WhiteboardTool;
+  color: WhiteboardColor;
+  width: WhiteboardWidth;
+  // [x, y, t-ms-since-stroke-start]
+  points: Array<[number, number, number]>;
+}
+
+interface Props {
+  strokes: WhiteboardStroke[];
+  tool: WhiteboardTool;
+  color: WhiteboardColor;
+  width: WhiteboardWidth;
+  onStroke: (payload: WhiteboardStrokePayload) => void;
+  logicalWidth?: number;
+  logicalHeight?: number;
+}
+
+const DEFAULT_LOGICAL_W = 1280;
+const DEFAULT_LOGICAL_H = 720;
+
+export function WhiteboardCanvas({
+  strokes,
+  tool,
+  color,
+  width,
+  onStroke,
+  logicalWidth = DEFAULT_LOGICAL_W,
+  logicalHeight = DEFAULT_LOGICAL_H,
+}: Props) {
+  const canvasRef = useRef<HTMLCanvasElement | null>(null);
+  const draftRef = useRef<WhiteboardStrokePayload | null>(null);
+  const strokeStartRef = useRef<number>(0);
+  const [, forceTick] = useState(0);
+
+  useEffect(() => {
+    const cv = canvasRef.current;
+    if (!cv) return;
+    cv.width = logicalWidth;
+    cv.height = logicalHeight;
+    const ctx = cv.getContext('2d');
+    if (!ctx) return;
+    ctx.fillStyle = '#ffffff';
+    ctx.fillRect(0, 0, cv.width, cv.height);
+    for (const s of strokes) {
+      const payload = s.strokeJson as Partial<WhiteboardStrokePayload> | null;
+      if (payload) renderStroke(ctx, payload);
+    }
+    if (draftRef.current) renderStroke(ctx, draftRef.current);
+  });
+
+  function canvasPoint(e: React.PointerEvent<HTMLCanvasElement>): [number, number] {
+    const cv = canvasRef.current!;
+    const rect = cv.getBoundingClientRect();
+    const scaleX = cv.width / rect.width;
+    const scaleY = cv.height / rect.height;
+    return [(e.clientX - rect.left) * scaleX, (e.clientY - rect.top) * scaleY];
+  }
+
+  const handlePointerDown = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    const cv = canvasRef.current;
+    if (!cv) return;
+    cv.setPointerCapture(e.pointerId);
+    const [x, y] = canvasPoint(e);
+    strokeStartRef.current = Date.now();
+    draftRef.current = {
+      tool,
+      color,
+      width,
+      points: [[x, y, 0]],
+    };
+    forceTick((n) => n + 1);
+  };
+
+  const handlePointerMove = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!draftRef.current) return;
+    const [x, y] = canvasPoint(e);
+    draftRef.current.points.push([x, y, Date.now() - strokeStartRef.current]);
+    forceTick((n) => n + 1);
+  };
+
+  const handlePointerUp = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    const cv = canvasRef.current;
+    if (cv && cv.hasPointerCapture(e.pointerId)) cv.releasePointerCapture(e.pointerId);
+    const draft = draftRef.current;
+    draftRef.current = null;
+    if (!draft) return;
+    if (draft.points.length < 2) {
+      forceTick((n) => n + 1);
+      return;
+    }
+    onStroke(draft);
+    forceTick((n) => n + 1);
+  };
+
+  return (
+    <canvas
+      ref={canvasRef}
+      onPointerDown={handlePointerDown}
+      onPointerMove={handlePointerMove}
+      onPointerUp={handlePointerUp}
+      onPointerLeave={handlePointerUp}
+      className="block max-h-full max-w-full cursor-crosshair touch-none rounded-lg border border-line/40 bg-white shadow-2xl"
+      style={{ aspectRatio: logicalWidth + ' / ' + logicalHeight, width: '100%' }}
+    />
+  );
+}
+
+function renderStroke(
+  ctx: CanvasRenderingContext2D,
+  s: Partial<WhiteboardStrokePayload>,
+): void {
+  const points = Array.isArray(s.points) ? s.points : null;
+  if (!points || points.length < 1) return;
+
+  ctx.save();
+  ctx.lineCap = 'round';
+  ctx.lineJoin = 'round';
+  ctx.lineWidth = typeof s.width === 'number' ? s.width : 4;
+  if (s.tool === 'eraser') {
+    ctx.strokeStyle = '#ffffff';
+    ctx.lineWidth = Math.max(8, (typeof s.width === 'number' ? s.width : 4) * 4);
+  } else {
+    ctx.strokeStyle = typeof s.color === 'string' ? s.color : '#000000';
+  }
+
+  ctx.beginPath();
+  ctx.moveTo(points[0]![0], points[0]![1]);
+  for (let i = 1; i < points.length; i++) {
+    ctx.lineTo(points[i]![0], points[i]![1]);
+  }
+  ctx.stroke();
+  ctx.restore();
+}

apps/desktop/src/components/WhiteboardModal.tsx

@@ -0,0 +1,197 @@
+import { useEffect, useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useWhiteboardStrokes } from '../hooks/useWhiteboardStrokes';
+import { XIcon } from './icons';
+import {
+  WhiteboardCanvas,
+  type WhiteboardColor,
+  type WhiteboardTool,
+  type WhiteboardWidth,
+} from './WhiteboardCanvas';
+
+interface Props {
+  whiteboardId: string;
+  onClose: () => void;
+}
+
+const COLORS: WhiteboardColor[] = ['#000000', '#ef4444', '#3b82f6', '#22c55e', '#facc15', '#a855f7'];
+const WIDTHS: WhiteboardWidth[] = [2, 4, 8];
+
+export function WhiteboardModal({ whiteboardId, onClose }: Props) {
+  const { t } = useTranslation();
+  const { strokes, loading, error, insertStroke, clearAll } = useWhiteboardStrokes(whiteboardId);
+  const [tool, setTool] = useState<WhiteboardTool>('pen');
+  const [color, setColor] = useState<WhiteboardColor>('#000000');
+  const [width, setWidth] = useState<WhiteboardWidth>(4);
+  const [confirmClear, setConfirmClear] = useState(false);
+
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') onClose();
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [onClose]);
+
+  const handleConfirmClear = async () => {
+    setConfirmClear(false);
+    try {
+      await clearAll();
+    } catch (err) {
+      console.error('clearAll failed', err);
+    }
+  };
+
+  return (
+    <div
+      role="dialog"
+      aria-modal="true"
+      aria-label={t('app:whiteboard.title', { defaultValue: 'Whiteboard' })}
+      className="fixed inset-0 z-[80] flex flex-col bg-ink-950/95"
+    >
+      <header className="flex shrink-0 items-center justify-between border-b border-line/40 bg-surface-2 px-4 py-2">
+        <h2 className="font-display text-sm font-semibold text-fg">
+          {t('app:whiteboard.title', { defaultValue: 'Whiteboard' })}
+        </h2>
+        <button
+          type="button"
+          onClick={onClose}
+          aria-label={t('app:whiteboard.close', { defaultValue: 'Schließen' })}
+          className="flex h-7 w-7 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-3 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </header>
+
+      <div className="flex min-h-0 flex-1 items-center justify-center overflow-hidden p-6">
+        {loading ? (
+          <p className="text-sm text-fg-muted">
+            {t('app:whiteboard.loading', { defaultValue: 'Lädt…' })}
+          </p>
+        ) : error ? (
+          <p className="text-sm text-rose-400">
+            {t('app:whiteboard.error', { defaultValue: 'Whiteboard konnte nicht geladen werden.' })}
+          </p>
+        ) : (
+          <WhiteboardCanvas
+            strokes={strokes}
+            tool={tool}
+            color={color}
+            width={width}
+            onStroke={(payload) => void insertStroke(payload)}
+          />
+        )}
+      </div>
+
+      <footer className="flex shrink-0 flex-wrap items-center gap-4 border-t border-line/40 bg-surface-2 px-4 py-3">
+        <div className="flex items-center gap-1">
+          {(['pen', 'eraser'] as WhiteboardTool[]).map((id) => {
+            const label = id === 'pen' ? 'Stift' : 'Radierer';
+            const active = tool === id;
+            return (
+              <button
+                key={id}
+                type="button"
+                onClick={() => setTool(id)}
+                aria-pressed={active}
+                title={label}
+                className={
+                  'flex h-8 w-8 cursor-pointer items-center justify-center rounded-md text-xs font-semibold transition ' +
+                  (active
+                    ? 'bg-accent/20 text-accent ring-2 ring-accent/40'
+                    : 'bg-surface-3 text-fg-muted hover:bg-surface hover:text-fg')
+                }
+              >
+                {id === 'pen' ? '✎' : '⌫'}
+              </button>
+            );
+          })}
+        </div>
+
+        <div className="h-6 w-px bg-line/40" aria-hidden />
+
+        <div className="flex items-center gap-1">
+          {COLORS.map((c) => {
+            const active = color === c;
+            return (
+              <button
+                key={c}
+                type="button"
+                onClick={() => setColor(c)}
+                aria-pressed={active}
+                aria-label={c}
+                className={
+                  'h-6 w-6 cursor-pointer rounded-full border-2 transition ' +
+                  (active ? 'border-fg scale-110' : 'border-line/40 hover:scale-105')
+                }
+                style={{ backgroundColor: c }}
+              />
+            );
+          })}
+        </div>
+
+        <div className="h-6 w-px bg-line/40" aria-hidden />
+
+        <div className="flex items-center gap-1">
+          {WIDTHS.map((w) => {
+            const active = width === w;
+            return (
+              <button
+                key={w}
+                type="button"
+                onClick={() => setWidth(w)}
+                aria-pressed={active}
+                title={w + 'px'}
+                className={
+                  'flex h-8 w-8 cursor-pointer items-center justify-center rounded-md transition ' +
+                  (active
+                    ? 'bg-accent/20 ring-2 ring-accent/40'
+                    : 'bg-surface-3 hover:bg-surface')
+                }
+              >
+                <div
+                  className="rounded-full bg-fg"
+                  style={{ width: w + 2 + 'px', height: w + 2 + 'px' }}
+                />
+              </button>
+            );
+          })}
+        </div>
+
+        <div className="ml-auto flex items-center gap-2">
+          {confirmClear ? (
+            <>
+              <span className="text-xs text-fg-muted">
+                {t('app:whiteboard.confirm_clear', { defaultValue: 'Alles löschen?' })}
+              </span>
+              <button
+                type="button"
+                onClick={() => setConfirmClear(false)}
+                className="cursor-pointer rounded-md border border-line bg-surface-3 px-3 py-1.5 text-xs font-medium text-fg-muted transition hover:bg-surface"
+              >
+                {t('app:whiteboard.cancel', { defaultValue: 'Abbrechen' })}
+              </button>
+              <button
+                type="button"
+                onClick={() => void handleConfirmClear()}
+                className="cursor-pointer rounded-md bg-rose-500 px-3 py-1.5 text-xs font-semibold text-white transition hover:bg-rose-500/90"
+              >
+                {t('app:whiteboard.confirm', { defaultValue: 'Ja, löschen' })}
+              </button>
+            </>
+          ) : (
+            <button
+              type="button"
+              onClick={() => setConfirmClear(true)}
+              disabled={strokes.length === 0}
+              className="cursor-pointer rounded-md border border-rose-500/40 bg-rose-500/10 px-3 py-1.5 text-xs font-semibold text-rose-600 transition hover:bg-rose-500/20 disabled:cursor-not-allowed disabled:opacity-50 dark:text-rose-300"
+            >
+              {t('app:whiteboard.clear_all', { defaultValue: 'Alles löschen' })}
+            </button>
+          )}
+        </div>
+      </footer>
+    </div>
+  );
+}

apps/desktop/src/components/icons.tsx

@@ -1,6 +1,7 @@
 // Inline SVG icons — no icon library dependency. Lucide-style stroke=1.75.
+import { memo } from 'react';
 
-type IconProps = React.SVGProps<SVGSVGElement>;
+type IconProps = React.ComponentPropsWithoutRef<'svg'>;
 
 function Base({ children, ...props }: IconProps & { children: React.ReactNode }) {
   return (
@@ -20,7 +21,7 @@ function Base({ children, ...props }: IconProps & { children: React.ReactNode })
   );
 }
 
-export function MailIcon(props: IconProps) {
+function MailIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="5" width="18" height="14" rx="2" />
@@ -28,8 +29,9 @@ export function MailIcon(props: IconProps) {
     </Base>
   );
 }
+export const MailIcon = memo(MailIconInner);
 
-export function AtIcon(props: IconProps) {
+function AtIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="4" />
@@ -37,8 +39,9 @@ export function AtIcon(props: IconProps) {
     </Base>
   );
 }
+export const AtIcon = memo(AtIconInner);
 
-export function TicketIcon(props: IconProps) {
+function TicketIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M3 8a2 2 0 0 1 2-2h14a2 2 0 0 1 2 2v2a2 2 0 1 0 0 4v2a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-2a2 2 0 1 0 0-4V8Z" />
@@ -46,8 +49,9 @@ export function TicketIcon(props: IconProps) {
     </Base>
   );
 }
+export const TicketIcon = memo(TicketIconInner);
 
-export function ArrowRightIcon(props: IconProps) {
+function ArrowRightIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M5 12h14" />
@@ -55,8 +59,9 @@ export function ArrowRightIcon(props: IconProps) {
     </Base>
   );
 }
+export const ArrowRightIcon = memo(ArrowRightIconInner);
 
-export function CheckCircleIcon(props: IconProps) {
+function CheckCircleIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="9" />
@@ -64,8 +69,9 @@ export function CheckCircleIcon(props: IconProps) {
     </Base>
   );
 }
+export const CheckCircleIcon = memo(CheckCircleIconInner);
 
-export function AlertIcon(props: IconProps) {
+function AlertIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M12 9v4" />
@@ -74,8 +80,9 @@ export function AlertIcon(props: IconProps) {
     </Base>
   );
 }
+export const AlertIcon = memo(AlertIconInner);
 
-export function ShieldIcon(props: IconProps) {
+function ShieldIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M12 3 4 6v6c0 5 3.5 8.5 8 9 4.5-.5 8-4 8-9V6l-8-3Z" />
@@ -83,8 +90,9 @@ export function ShieldIcon(props: IconProps) {
     </Base>
   );
 }
+export const ShieldIcon = memo(ShieldIconInner);
 
-export function LockIcon(props: IconProps) {
+function LockIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="4" y="11" width="16" height="10" rx="2" />
@@ -92,8 +100,9 @@ export function LockIcon(props: IconProps) {
     </Base>
   );
 }
+export const LockIcon = memo(LockIconInner);
 
-export function WifiLowIcon(props: IconProps) {
+function WifiLowIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M5 12.55a11 11 0 0 1 14 0" opacity="0.35" />
@@ -102,8 +111,9 @@ export function WifiLowIcon(props: IconProps) {
     </Base>
   );
 }
+export const WifiLowIcon = memo(WifiLowIconInner);
 
-export function WifiOffIcon(props: IconProps) {
+function WifiOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m2 2 20 20" />
@@ -116,8 +126,9 @@ export function WifiOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const WifiOffIcon = memo(WifiOffIconInner);
 
-export function PinIcon(props: IconProps) {
+function PinIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M12 17v5" />
@@ -125,8 +136,9 @@ export function PinIcon(props: IconProps) {
     </Base>
   );
 }
+export const PinIcon = memo(PinIconInner);
 
-export function EyeOffIcon(props: IconProps) {
+function EyeOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m2 2 20 20" />
@@ -136,8 +148,9 @@ export function EyeOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const EyeOffIcon = memo(EyeOffIconInner);
 
-export function CaptionsIcon(props: IconProps) {
+function CaptionsIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="6" width="18" height="12" rx="2" />
@@ -146,8 +159,9 @@ export function CaptionsIcon(props: IconProps) {
     </Base>
   );
 }
+export const CaptionsIcon = memo(CaptionsIconInner);
 
-export function PinOffIcon(props: IconProps) {
+function PinOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m2 2 20 20" />
@@ -157,8 +171,9 @@ export function PinOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const PinOffIcon = memo(PinOffIconInner);
 
-export function SparklesIcon(props: IconProps) {
+function SparklesIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M12 3v4" />
@@ -172,8 +187,9 @@ export function SparklesIcon(props: IconProps) {
     </Base>
   );
 }
+export const SparklesIcon = memo(SparklesIconInner);
 
-export function SpinnerIcon(props: IconProps) {
+function SpinnerIconInner(props: IconProps) {
   return (
     <svg
       xmlns="http://www.w3.org/2000/svg"
@@ -208,16 +224,18 @@ export function SpinnerIcon(props: IconProps) {
     </svg>
   );
 }
+export const SpinnerIcon = memo(SpinnerIconInner);
 
-export function ChatBubbleIcon(props: IconProps) {
+function ChatBubbleIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M21 15a2 2 0 0 1-2 2H8l-5 4V5a2 2 0 0 1 2-2h14a2 2 0 0 1 2 2Z" />
     </Base>
   );
 }
+export const ChatBubbleIcon = memo(ChatBubbleIconInner);
 
-export function UsersIcon(props: IconProps) {
+function UsersIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M16 21v-2a4 4 0 0 0-4-4H6a4 4 0 0 0-4 4v2" />
@@ -227,8 +245,9 @@ export function UsersIcon(props: IconProps) {
     </Base>
   );
 }
+export const UsersIcon = memo(UsersIconInner);
 
-export function GearIcon(props: IconProps) {
+function GearIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="3" />
@@ -236,8 +255,9 @@ export function GearIcon(props: IconProps) {
     </Base>
   );
 }
+export const GearIcon = memo(GearIconInner);
 
-export function SearchIcon(props: IconProps) {
+function SearchIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="11" cy="11" r="7" />
@@ -245,16 +265,18 @@ export function SearchIcon(props: IconProps) {
     </Base>
   );
 }
+export const SearchIcon = memo(SearchIconInner);
 
-export function PlusIcon(props: IconProps) {
+function PlusIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M12 5v14M5 12h14" />
     </Base>
   );
 }
+export const PlusIcon = memo(PlusIconInner);
 
-export function SignOutIcon(props: IconProps) {
+function SignOutIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4" />
@@ -263,32 +285,36 @@ export function SignOutIcon(props: IconProps) {
     </Base>
   );
 }
+export const SignOutIcon = memo(SignOutIconInner);
 
-export function MenuIcon(props: IconProps) {
+function MenuIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M3 6h18M3 12h18M3 18h18" />
     </Base>
   );
 }
+export const MenuIcon = memo(MenuIconInner);
 
-export function ChevronDownIcon(props: IconProps) {
+function ChevronDownIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m6 9 6 6 6-6" />
     </Base>
   );
 }
+export const ChevronDownIcon = memo(ChevronDownIconInner);
 
-export function PencilIcon(props: IconProps) {
+function PencilIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M17 3a2.85 2.83 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5Z" />
     </Base>
   );
 }
+export const PencilIcon = memo(PencilIconInner);
 
-export function TrashIcon(props: IconProps) {
+function TrashIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M3 6h18" />
@@ -299,8 +325,9 @@ export function TrashIcon(props: IconProps) {
     </Base>
   );
 }
+export const TrashIcon = memo(TrashIconInner);
 
-export function SmileIcon(props: IconProps) {
+function SmileIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="9" />
@@ -310,8 +337,9 @@ export function SmileIcon(props: IconProps) {
     </Base>
   );
 }
+export const SmileIcon = memo(SmileIconInner);
 
-export function CopyIcon(props: IconProps) {
+function CopyIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="9" y="9" width="13" height="13" rx="2" />
@@ -319,16 +347,18 @@ export function CopyIcon(props: IconProps) {
     </Base>
   );
 }
+export const CopyIcon = memo(CopyIconInner);
 
-export function PhoneIcon(props: IconProps) {
+function PhoneIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M22 16.92v3a2 2 0 0 1-2.18 2 19.79 19.79 0 0 1-8.63-3.07 19.5 19.5 0 0 1-6-6A19.79 19.79 0 0 1 2.12 4.18 2 2 0 0 1 4.11 2h3a2 2 0 0 1 2 1.72c.127.96.361 1.903.7 2.81a2 2 0 0 1-.45 2.11L8.09 9.91a16 16 0 0 0 6 6l1.27-1.27a2 2 0 0 1 2.11-.45c.907.339 1.85.573 2.81.7A2 2 0 0 1 22 16.92Z" />
     </Base>
   );
 }
+export const PhoneIcon = memo(PhoneIconInner);
 
-export function PhoneOffIcon(props: IconProps) {
+function PhoneOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M10.68 13.31a16 16 0 0 0 3.41 2.6l1.27-1.27a2 2 0 0 1 2.11-.45c.907.339 1.85.573 2.81.7A2 2 0 0 1 22 16.92v3a2 2 0 0 1-2.18 2 19.79 19.79 0 0 1-8.63-3.07 19.5 19.5 0 0 1-3.48-3.05" />
@@ -337,8 +367,9 @@ export function PhoneOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const PhoneOffIcon = memo(PhoneOffIconInner);
 
-export function MicIcon(props: IconProps) {
+function MicIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="9" y="2" width="6" height="12" rx="3" />
@@ -348,8 +379,9 @@ export function MicIcon(props: IconProps) {
     </Base>
   );
 }
+export const MicIcon = memo(MicIconInner);
 
-export function MicOffIcon(props: IconProps) {
+function MicOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M1 1l22 22" />
@@ -362,8 +394,9 @@ export function MicOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const MicOffIcon = memo(MicOffIconInner);
 
-export function InfoIcon(props: IconProps) {
+function InfoIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="9" />
@@ -372,16 +405,18 @@ export function InfoIcon(props: IconProps) {
     </Base>
   );
 }
+export const InfoIcon = memo(InfoIconInner);
 
-export function XIcon(props: IconProps) {
+function XIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M18 6 6 18M6 6l12 12" />
     </Base>
   );
 }
+export const XIcon = memo(XIconInner);
 
-export function MonitorShareIcon(props: IconProps) {
+function MonitorShareIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="4" width="18" height="12" rx="2" />
@@ -390,8 +425,9 @@ export function MonitorShareIcon(props: IconProps) {
     </Base>
   );
 }
+export const MonitorShareIcon = memo(MonitorShareIconInner);
 
-export function MonitorStopIcon(props: IconProps) {
+function MonitorStopIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="4" width="18" height="12" rx="2" />
@@ -400,8 +436,9 @@ export function MonitorStopIcon(props: IconProps) {
     </Base>
   );
 }
+export const MonitorStopIcon = memo(MonitorStopIconInner);
 
-export function SunIcon(props: IconProps) {
+function SunIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="12" r="4" />
@@ -409,16 +446,18 @@ export function SunIcon(props: IconProps) {
     </Base>
   );
 }
+export const SunIcon = memo(SunIconInner);
 
-export function MoonIcon(props: IconProps) {
+function MoonIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M21 12.79A9 9 0 1 1 11.21 3a7 7 0 0 0 9.79 9.79Z" />
     </Base>
   );
 }
+export const MoonIcon = memo(MoonIconInner);
 
-export function GridIcon(props: IconProps) {
+function GridIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="3" width="7" height="7" rx="1.5" />
@@ -428,8 +467,9 @@ export function GridIcon(props: IconProps) {
     </Base>
   );
 }
+export const GridIcon = memo(GridIconInner);
 
-export function ImageIcon(props: IconProps) {
+function ImageIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="5" width="18" height="14" rx="2" />
@@ -438,8 +478,9 @@ export function ImageIcon(props: IconProps) {
     </Base>
   );
 }
+export const ImageIcon = memo(ImageIconInner);
 
-export function FileIcon(props: IconProps) {
+function FileIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M14 2H7a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h10a2 2 0 0 0 2-2V7Z" />
@@ -447,8 +488,9 @@ export function FileIcon(props: IconProps) {
     </Base>
   );
 }
+export const FileIcon = memo(FileIconInner);
 
-export function PollIcon(props: IconProps) {
+function PollIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M5 19V9" />
@@ -458,8 +500,9 @@ export function PollIcon(props: IconProps) {
     </Base>
   );
 }
+export const PollIcon = memo(PollIconInner);
 
-export function FocusIcon(props: IconProps) {
+function FocusIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="3" width="18" height="18" rx="2" />
@@ -467,8 +510,9 @@ export function FocusIcon(props: IconProps) {
     </Base>
   );
 }
+export const FocusIcon = memo(FocusIconInner);
 
-export function MaximizeIcon(props: IconProps) {
+function MaximizeIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M4 9V5a1 1 0 0 1 1-1h4" />
@@ -478,8 +522,9 @@ export function MaximizeIcon(props: IconProps) {
     </Base>
   );
 }
+export const MaximizeIcon = memo(MaximizeIconInner);
 
-export function VideoIcon(props: IconProps) {
+function VideoIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="2" y="6" width="15" height="12" rx="2" />
@@ -487,16 +532,18 @@ export function VideoIcon(props: IconProps) {
     </Base>
   );
 }
+export const VideoIcon = memo(VideoIconInner);
 
-export function CrownIcon(props: IconProps) {
+function CrownIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m3 7 4 4 5-6 5 6 4-4v10a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V7Z" />
     </Base>
   );
 }
+export const CrownIcon = memo(CrownIconInner);
 
-export function MusicIcon(props: IconProps) {
+function MusicIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M9 18V5l12-2v13" />
@@ -505,16 +552,18 @@ export function MusicIcon(props: IconProps) {
     </Base>
   );
 }
+export const MusicIcon = memo(MusicIconInner);
 
-export function SendIcon(props: IconProps) {
+function SendIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="m3 11 18-8-8 18-2-8-8-2Z" />
     </Base>
   );
 }
+export const SendIcon = memo(SendIconInner);
 
-export function ArchiveIcon(props: IconProps) {
+function ArchiveIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <rect x="3" y="4" width="18" height="5" rx="1" />
@@ -523,8 +572,9 @@ export function ArchiveIcon(props: IconProps) {
     </Base>
   );
 }
+export const ArchiveIcon = memo(ArchiveIconInner);
 
-export function BellIcon(props: IconProps) {
+function BellIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M6 8a6 6 0 1 1 12 0c0 4 1.5 5 2 6H4c.5-1 2-2 2-6Z" />
@@ -532,8 +582,9 @@ export function BellIcon(props: IconProps) {
     </Base>
   );
 }
+export const BellIcon = memo(BellIconInner);
 
-export function BellOffIcon(props: IconProps) {
+function BellOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M9.5 18a2.5 2.5 0 0 0 5 0" />
@@ -545,8 +596,9 @@ export function BellOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const BellOffIcon = memo(BellOffIconInner);
 
-export function MoreVerticalIcon(props: IconProps) {
+function MoreVerticalIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <circle cx="12" cy="5" r="1.5" />
@@ -555,8 +607,9 @@ export function MoreVerticalIcon(props: IconProps) {
     </Base>
   );
 }
+export const MoreVerticalIcon = memo(MoreVerticalIconInner);
 
-export function HeadphonesIcon(props: IconProps) {
+function HeadphonesIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M3 14v-2a9 9 0 0 1 18 0v2" />
@@ -565,8 +618,9 @@ export function HeadphonesIcon(props: IconProps) {
     </Base>
   );
 }
+export const HeadphonesIcon = memo(HeadphonesIconInner);
 
-export function HeadphonesOffIcon(props: IconProps) {
+function HeadphonesOffIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M3 14v-2a9 9 0 0 1 11.3-8.7" />
@@ -577,8 +631,9 @@ export function HeadphonesOffIcon(props: IconProps) {
     </Base>
   );
 }
+export const HeadphonesOffIcon = memo(HeadphonesOffIconInner);
 
-export function ReplyIcon(props: IconProps) {
+function ReplyIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <polyline points="9 17 4 12 9 7" />
@@ -586,8 +641,9 @@ export function ReplyIcon(props: IconProps) {
     </Base>
   );
 }
+export const ReplyIcon = memo(ReplyIconInner);
 
-export function ForwardIcon(props: IconProps) {
+function ForwardIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <polyline points="15 17 20 12 15 7" />
@@ -595,16 +651,18 @@ export function ForwardIcon(props: IconProps) {
     </Base>
   );
 }
+export const ForwardIcon = memo(ForwardIconInner);
 
-export function ChevronUpIcon(props: IconProps) {
+function ChevronUpIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <polyline points="18 15 12 9 6 15" />
     </Base>
   );
 }
+export const ChevronUpIcon = memo(ChevronUpIconInner);
 
-export function AddUserIcon(props: IconProps) {
+function AddUserIconInner(props: IconProps) {
   return (
     <Base {...props}>
       <path d="M16 21v-2a4 4 0 0 0-4-4H6a4 4 0 0 0-4 4v2" />
@@ -613,12 +671,13 @@ export function AddUserIcon(props: IconProps) {
     </Base>
   );
 }
+export const AddUserIcon = memo(AddUserIconInner);
 
 // Soft-N mark: rounded-square violet tile with a stylised "N" glyph. Used
 // wherever the app needs a standalone icon (sidebar rail, auth screen,
 // favicon). Colour decisions sit inside the SVG so consumers just size the
 // element via `className`.
-export function LogoMark(props: IconProps) {
+function LogoMarkInner(props: IconProps) {
   return (
     <svg
       xmlns="http://www.w3.org/2000/svg"
@@ -638,10 +697,11 @@ export function LogoMark(props: IconProps) {
     </svg>
   );
 }
+export const LogoMark = memo(LogoMarkInner);
 
 // Full lockup: soft-N mark + "Netralax" wordmark. `tone` decides text colour:
 // "dark" = white text (use on dark background), "light" = near-black.
-export function LogoLockup({
+function LogoLockupInner({
   tone = 'dark',
   ...props
 }: IconProps & { tone?: 'dark' | 'light' }) {
@@ -676,3 +736,4 @@ export function LogoLockup({
     </svg>
   );
 }
+export const LogoLockup = memo(LogoLockupInner);

apps/desktop/src/components/settings/DeviceListTab.tsx

@@ -0,0 +1,126 @@
+import { useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useOwnDevices } from '../../hooks/useOwnDevices';
+import { getDeviceRowId } from '../../lib/deviceRowId';
+import { SpinnerIcon } from '../icons';
+
+function formatLastSeen(iso: string, locale: string): string {
+  try {
+    const d = new Date(iso);
+    return d.toLocaleString(locale, { dateStyle: 'medium', timeStyle: 'short' });
+  } catch {
+    return iso;
+  }
+}
+
+export function DeviceListTab() {
+  const { t, i18n } = useTranslation();
+  const { devices, loading, error, revoke } = useOwnDevices();
+  const ownId = getDeviceRowId();
+  const [busy, setBusy] = useState<string | null>(null);
+  const [opError, setOpError] = useState<string | null>(null);
+
+  const handleRevoke = async (id: string) => {
+    setOpError(null);
+    setBusy(id);
+    try {
+      await revoke(id);
+    } catch (err) {
+      setOpError(err instanceof Error ? err.message : 'revoke failed');
+    } finally {
+      setBusy(null);
+    }
+  };
+
+  if (loading) {
+    return (
+      <div className="flex items-center justify-center py-10 text-fg-muted">
+        <SpinnerIcon className="h-5 w-5" />
+      </div>
+    );
+  }
+
+  if (error) {
+    return (
+      <p className="rounded-lg border border-rose-500/40 bg-rose-500/10 px-4 py-3 text-sm text-rose-600 dark:text-rose-300">
+        {t('app:settings.devices.error', { defaultValue: 'Geräteliste konnte nicht geladen werden.' })}
+      </p>
+    );
+  }
+
+  if (devices.length === 0) {
+    return (
+      <p className="text-sm text-fg-muted">
+        {t('app:settings.devices.empty', { defaultValue: 'Noch keine Geräte angemeldet.' })}
+      </p>
+    );
+  }
+
+  return (
+    <div className="space-y-3">
+      {opError && (
+        <p className="rounded-lg border border-rose-500/40 bg-rose-500/10 px-4 py-2 text-sm text-rose-600 dark:text-rose-300">
+          {opError}
+        </p>
+      )}
+      <ul className="space-y-2">
+        {devices.map((d) => {
+          const isOwn = d.id === ownId;
+          const isRevoked = d.revokedAt !== null;
+          return (
+            <li
+              key={d.id}
+              className="flex items-center gap-3 rounded-lg border border-line bg-surface-2 px-4 py-3"
+            >
+              <div className="min-w-0 flex-1">
+                <div className="flex items-center gap-2">
+                  <span className="truncate text-sm font-medium text-fg">{d.name}</span>
+                  {isOwn && (
+                    <span className="rounded-md bg-accent/15 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-accent">
+                      {t('app:settings.devices.this_device', { defaultValue: 'Dieses Gerät' })}
+                    </span>
+                  )}
+                  {isRevoked && (
+                    <span className="rounded-md bg-rose-500/15 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide text-rose-600 dark:text-rose-300">
+                      {t('app:settings.devices.revoked', { defaultValue: 'Abgemeldet' })}
+                    </span>
+                  )}
+                </div>
+                <p className="mt-0.5 text-xs text-fg-muted">
+                  {d.platform} · {t('app:settings.devices.last_seen', { defaultValue: 'zuletzt' })}{' '}
+                  {formatLastSeen(d.lastSeenAt, i18n.language)}
+                </p>
+              </div>
+              {isOwn ? (
+                <button
+                  type="button"
+                  disabled
+                  title={t('app:settings.devices.use_sign_out', { defaultValue: 'Nutze Sign-out' })}
+                  className="cursor-not-allowed rounded-md border border-line bg-surface-3 px-3 py-1.5 text-xs font-medium text-fg-muted opacity-60"
+                >
+                  {t('app:settings.devices.use_sign_out', { defaultValue: 'Nutze Sign-out' })}
+                </button>
+              ) : isRevoked ? (
+                <span className="text-xs text-fg-muted">
+                  {t('app:settings.devices.already_revoked', { defaultValue: '—' })}
+                </span>
+              ) : (
+                <button
+                  type="button"
+                  onClick={() => void handleRevoke(d.id)}
+                  disabled={busy === d.id}
+                  className="cursor-pointer rounded-md border border-rose-500/40 bg-rose-500/10 px-3 py-1.5 text-xs font-semibold text-rose-600 transition hover:bg-rose-500/20 disabled:cursor-wait disabled:opacity-60 dark:text-rose-300"
+                >
+                  {busy === d.id
+                    ? t('app:settings.devices.revoking', { defaultValue: 'Wird abgemeldet…' })
+                    : t('app:settings.devices.revoke', { defaultValue: 'Abmelden' })}
+                </button>
+              )}
+            </li>
+          );
+        })}
+      </ul>
+    </div>
+  );
+}

apps/desktop/src/context/AuthContext.tsx

@@ -1,11 +1,15 @@
 import {
   fetchUserKeyBlob,
   getOwnProfile,
+  listOwnDevices,
+  registerDevice,
   signOut as supabaseSignOut,
+  touchDeviceLastSeen,
   type Profile,
   updateOwnProfile,
 } from '@chat-app/shared/auth';
 import { changeLocale, isSupportedLocale } from '@chat-app/shared/i18n';
+import type { DevicePlatform } from '@chat-app/shared/supabase';
 import type { Session } from '@supabase/supabase-js';
 import {
   createContext,
@@ -19,7 +23,10 @@ import {
 } from 'react';
 import { useTranslation } from 'react-i18next';
 
+import { clearDeviceRowId, getDeviceRowId, setDeviceRowId } from '../lib/deviceRowId';
 import { ensureInstallId } from '../lib/installId';
+import { wipeLocalState } from '../lib/memoryWipe';
+import { isWipeOnCloseEnabled } from '../lib/memoryWipeSettings';
 import { setSecretStoreUser } from '../lib/secretStore';
 import { supabase } from '../lib/supabase';
 import { cachedUserKey, ensureLegacyMigrated } from '../lib/userIdentity';
@@ -48,6 +55,8 @@ interface AuthContextValue {
   refreshProfile: () => Promise<void>;
   refreshUserKeyState: () => Promise<void>;
   signOut: () => Promise<void>;
+  revokedRemotely: boolean;
+  acknowledgeRevocation: () => void;
 }
 
 const AuthContext = createContext<AuthContextValue | null>(null);
@@ -58,6 +67,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
   const [ready, setReady] = useState(false);
   const [profile, setProfile] = useState<Profile | null>(null);
   const [userKeyState, setUserKeyState] = useState<UserKeyState>({ status: 'loading' });
+  const [revokedRemotely, setRevokedRemotely] = useState(false);
   const autoOnlineUserRef = useRef<string | null>(null);
 
   // Initial session + auth subscription. We verify the cached JWT against the
@@ -194,6 +204,78 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     void registerWebPush(installId);
   }, [session]);
 
+  // Pre-warm Supabase: fires the first round-trip in the background so the
+  // first user-triggered query (e.g. loading conversations) doesn't pay
+  // the cold-connection latency.
+  useEffect(() => {
+    if (!session) return;
+    void supabase.from('profiles').select('id').limit(1).then(() => undefined);
+  }, [session]);
+
+  // Phase 3: ensure this install owns exactly one devices row. The row is
+  // pure session-list telemetry — it does not carry any cryptographic
+  // material since the per-user-key refactor. We re-use the row across
+  // restarts via localStorage (chatapp.deviceRowId.v1); a memory-wipe is
+  // intentionally treated as "new install".
+  useEffect(() => {
+    if (!session) return;
+    let cancelled = false;
+    void (async () => {
+      try {
+        const existing = getDeviceRowId();
+        if (existing) {
+          const rows = await listOwnDevices(supabase);
+          const match = rows.find((r) => r.id === existing && r.revokedAt === null);
+          if (match) {
+            await touchDeviceLastSeen(supabase, existing).catch(() => {});
+            return;
+          }
+          // Row gone / revoked: drop the stale id and fall through to
+          // registering a fresh one.
+          clearDeviceRowId();
+        }
+        if (cancelled) return;
+        const hostname =
+          (typeof window.electronAPI?.getHostname === 'function'
+            ? await window.electronAPI.getHostname().catch(() => null)
+            : null) ?? 'Desktop';
+        // Map Node's process.platform values to the schema's device_platform
+        // enum ('windows' | 'macos' | 'linux' | 'ios' | 'android'). Default
+        // to 'linux' for unknown/web-build cases — the field is only used
+        // for the session-list UI icon.
+        const osPlatform = window.electronAPI?.osPlatform;
+        const platform: DevicePlatform =
+          osPlatform === 'win32'
+            ? 'windows'
+            : osPlatform === 'darwin'
+              ? 'macos'
+              : 'linux';
+        const created = await registerDevice(supabase, {
+          name: hostname.slice(0, 64),
+          platform,
+        });
+        if (!cancelled) setDeviceRowId(created.id);
+      } catch (err) {
+        console.warn('ensure device row failed', err);
+      }
+    })();
+    return () => {
+      cancelled = true;
+    };
+  }, [session]);
+
+  // Wipe-on-close: register a handler the main process pings on `before-quit`
+  // when the user has enabled the Settings → Sicherheit toggle. No-op outside
+  // Electron (web build has no preload bridge) or when the toggle is off.
+  useEffect(() => {
+    if (typeof window.electronAPI?.onWipeBeforeQuit !== 'function') return;
+    const unsub = window.electronAPI.onWipeBeforeQuit(async () => {
+      if (!isWipeOnCloseEnabled()) return;
+      await wipeLocalState(session?.user.id ?? null);
+    });
+    return unsub;
+  }, [session?.user.id]);
+
   // Auto online/offline transition.
   //
   // - On mount with a session whose last persisted state is `offline`, flip
@@ -235,12 +317,54 @@ export function AuthProvider({ children }: { children: ReactNode }) {
   }, [session, profile, refreshProfile]);
 
   const signOut = useCallback(async () => {
+    const uid = session?.user.id ?? null;
     await updateOwnProfile(supabase, { presenceState: 'offline' }).catch((err: unknown) => {
       console.warn('offline update before sign-out failed', err);
     });
     await supabaseSignOut(supabase);
+    await wipeLocalState(uid);
+  }, [session]);
+
+  const acknowledgeRevocation = useCallback(() => {
+    setRevokedRemotely(false);
   }, []);
 
+  // Phase 3: listen for own-device revocations. The same channel also fires
+  // when *another* of the user's installs is revoked — we ignore those (we
+  // only force-sign-out when OUR row's revoked_at flips). The UI's device
+  // list refetches independently via its own subscription in useOwnDevices.
+  useEffect(() => {
+    if (!session) return;
+    const userId = session.user.id;
+    const channel = supabase
+      .channel('devices:self:' + userId)
+      .on(
+        'postgres_changes',
+        {
+          event: 'UPDATE',
+          schema: 'public',
+          table: 'devices',
+          filter: 'user_id=eq.' + userId,
+        },
+        (payload) => {
+          const ownId = getDeviceRowId();
+          const row = payload.new as { id?: string; revoked_at?: string | null } | null;
+          if (!row || !ownId) return;
+          if (row.id !== ownId) return;
+          if (row.revoked_at) {
+            setRevokedRemotely(true);
+            void signOut().catch((err) => {
+              console.warn('forced signOut after revoke failed', err);
+            });
+          }
+        },
+      )
+      .subscribe();
+    return () => {
+      void supabase.removeChannel(channel);
+    };
+  }, [session, signOut]);
+
   const value = useMemo<AuthContextValue>(
     () => ({
       session,
@@ -250,8 +374,20 @@ export function AuthProvider({ children }: { children: ReactNode }) {
       refreshProfile,
       refreshUserKeyState,
       signOut,
+      revokedRemotely,
+      acknowledgeRevocation,
     }),
-    [session, profile, userKeyState, ready, refreshProfile, refreshUserKeyState, signOut],
+    [
+      session,
+      profile,
+      userKeyState,
+      ready,
+      refreshProfile,
+      refreshUserKeyState,
+      signOut,
+      revokedRemotely,
+      acknowledgeRevocation,
+    ],
   );
 
   return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>;

apps/desktop/src/context/CallContext.tsx

@@ -1442,20 +1442,29 @@ export function CallProvider({ children }: { children: ReactNode }) {
           // the same system audio twice and Chromium's version would
           // include our own renderer playback.
           audio: preferNativeLoopback ? false : wantAudio,
+          // Preset dims are passed as `ideal` constraints (not fixed width/height)
+          // so Chromium picks the closest match preserving the source's aspect
+          // ratio instead of CROPPING non-matching monitors. Without this, a 16:10
+          // monitor (1920×1200, 2560×1600) streamed under a 16:9 preset loses its
+          // bottom strip — including the Windows taskbar.
+          //
+          // LiveKit's VideoResolution types declare width/height as `number`, but
+          // Chromium's getDisplayMedia accepts the full MediaTrackConstraints shape
+          // including { ideal: N } objects — we cast through `unknown` to satisfy tsc.
           ...(ssParams.dims
             ? {
                 resolution: {
-                  width: ssParams.dims.width,
-                  height: ssParams.dims.height,
+                  width: { ideal: ssParams.dims.width },
+                  height: { ideal: ssParams.dims.height },
                   frameRate: fps,
-                },
+                } as unknown as { width: number; height: number; frameRate: number },
               }
             : {
                 resolution: {
-                  width: 3840,
-                  height: 2160,
                   frameRate: fps,
-                },
+                  width: undefined,
+                  height: undefined,
+                } as unknown as { width: number; height: number; frameRate: number },
               }),
           ...(displaySurface
             ? ({ displaySurface } as { displaySurface: DisplaySurfaceHint })
@@ -2004,14 +2013,16 @@ export function CallProvider({ children }: { children: ReactNode }) {
 
     const syncGlobalShortcuts = () => {
       if (!isTauriRuntime()) return;
+      // Only register an OS-level shortcut if the user explicitly opted in.
+      // Window-scoped firing happens via the `onKey` listener above and works
+      // for every enabled binding regardless of the `global` flag.
+      const enabledAndGlobal = (b: VoiceHotkeys[HotkeyKind]) => b.enabled && b.global;
       const desired: Record<HotkeyKind, string | null> = {
-        mute: settings.mute.enabled ? bindingToTauriShortcut(settings.mute) : null,
-        deafen: settings.deafen.enabled ? bindingToTauriShortcut(settings.deafen) : null,
-        hangup: settings.hangup.enabled ? bindingToTauriShortcut(settings.hangup) : null,
-        screenShare: settings.screenShare.enabled
-          ? bindingToTauriShortcut(settings.screenShare)
-          : null,
-        video: settings.video.enabled ? bindingToTauriShortcut(settings.video) : null,
+        mute:        enabledAndGlobal(settings.mute)        ? bindingToTauriShortcut(settings.mute)        : null,
+        deafen:      enabledAndGlobal(settings.deafen)      ? bindingToTauriShortcut(settings.deafen)      : null,
+        hangup:      enabledAndGlobal(settings.hangup)      ? bindingToTauriShortcut(settings.hangup)      : null,
+        screenShare: enabledAndGlobal(settings.screenShare) ? bindingToTauriShortcut(settings.screenShare) : null,
+        video:       enabledAndGlobal(settings.video)       ? bindingToTauriShortcut(settings.video)       : null,
       };
       for (const kind of KINDS) {
         const want = desired[kind];

apps/desktop/src/context/ConversationsContext.tsx

@@ -54,6 +54,15 @@ interface ConversationsContextValue {
   refresh: () => Promise<void>;
   markRead: (conversationId: string) => void;
   setActiveConversation: (conversationId: string | null) => void;
+  // Optimistic patch for the caller's per-membership preferences (mute /
+  // mentions-only / archive). Mutations to `conversation_members` echo back
+  // via the realtime channel and `refresh()` reconciles canonically, but the
+  // ~100-200ms roundtrip leaves the UI looking unresponsive. Callers patch
+  // immediately, snapshot the previous state, and roll back on failure.
+  patchConversation: (
+    conversationId: string,
+    patch: Partial<Pick<ConversationSummary, 'archived' | 'mutedUntil' | 'mentionsOnly'>>,
+  ) => void;
 }
 
 const ConversationsContext = createContext<ConversationsContextValue | null>(null);
@@ -164,6 +173,19 @@ export function ConversationsProvider({ children }: { children: ReactNode }) {
     [markRead],
   );
 
+  const patchConversation = useCallback<ConversationsContextValue['patchConversation']>(
+    (convId, patch) => {
+      setConversations((prev) => {
+        const idx = prev.findIndex((c) => c.id === convId);
+        if (idx === -1) return prev;
+        const next = [...prev];
+        next[idx] = { ...next[idx]!, ...patch };
+        return next;
+      });
+    },
+    [],
+  );
+
   useEffect(() => {
     if (!myId) {
       setConversations([]);
@@ -225,7 +247,12 @@ export function ConversationsProvider({ children }: { children: ReactNode }) {
                 (c) => c.id === row.conversation_id,
               );
               const muted = isConversationMuted(convForMute?.mutedUntil ?? null);
-              if (presenceRef.current !== 'dnd' && !muted) {
+              // "Mentions only" silences non-mention messages here. Mentions
+              // still fire via the independent useMentionNotifications
+              // subscription on message_mentions, so this branch doesn't
+              // lose the @-alerts.
+              const mentionsOnly = convForMute?.mentionsOnly ?? false;
+              if (presenceRef.current !== 'dnd' && !muted && !mentionsOnly) {
                 playNotificationTone();
                 const conv = conversationsRef.current.find(
                   (c) => c.id === row.conversation_id,
@@ -303,6 +330,7 @@ export function ConversationsProvider({ children }: { children: ReactNode }) {
       refresh,
       markRead,
       setActiveConversation,
+      patchConversation,
     }),
     [
       conversations,
@@ -313,6 +341,7 @@ export function ConversationsProvider({ children }: { children: ReactNode }) {
       refresh,
       markRead,
       setActiveConversation,
+      patchConversation,
     ],
   );
 

apps/desktop/src/hooks/useGame.ts

@@ -0,0 +1,75 @@
+import { useCallback, useEffect, useState } from 'react';
+
+import { getGame, makeGameMove, type GameRecord } from '@chat-app/shared/chat';
+
+import { supabase } from '../lib/supabase';
+
+export function useGame(gameId: string | null): {
+  game: GameRecord | null;
+  loading: boolean;
+  error: string | null;
+  makeMove: (move: object) => Promise<void>;
+} {
+  const [game, setGame] = useState<GameRecord | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    if (!gameId) {
+      setGame(null);
+      setLoading(false);
+      setError(null);
+      return;
+    }
+    let cancelled = false;
+    void (async () => {
+      try {
+        setLoading(true);
+        setError(null);
+        const fresh = await getGame(supabase, gameId);
+        if (!cancelled) {
+          setGame(fresh);
+          setLoading(false);
+        }
+      } catch (err) {
+        if (!cancelled) {
+          setLoading(false);
+          setError(err instanceof Error ? err.message : 'failed to load game');
+        }
+      }
+    })();
+    const channel = supabase
+      .channel('game:' + gameId)
+      .on(
+        'postgres_changes',
+        {
+          event: 'UPDATE',
+          schema: 'public',
+          table: 'conversation_games',
+          filter: 'id=eq.' + gameId,
+        },
+        () => {
+          void getGame(supabase, gameId)
+            .then((fresh) => { if (fresh) setGame(fresh); })
+            .catch((err) => { console.warn('game realtime refetch failed', err); });
+        },
+      )
+      .subscribe();
+    return () => {
+      cancelled = true;
+      void supabase.removeChannel(channel);
+    };
+  }, [gameId]);
+
+  const makeMove = useCallback(async (move: object) => {
+    if (!gameId) return;
+    try {
+      await makeGameMove(supabase, { gameId, move });
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'move failed');
+      throw err;
+    }
+  }, [gameId]);
+
+  return { game, loading, error, makeMove };
+}

apps/desktop/src/hooks/useIdleAutoLock.ts

@@ -0,0 +1,79 @@
+import { useEffect, useRef } from 'react';
+
+import { useAuth } from '../context/AuthContext';
+import {
+  getAutoLockMinutes,
+  subscribeAutoLockSetting,
+  type AutoLockMinutes,
+} from '../lib/autoLockSettings';
+
+const ACTIVITY_EVENTS: Array<keyof WindowEventMap> = [
+  'keydown',
+  'mousedown',
+  'pointermove',
+  'touchstart',
+  'wheel',
+];
+
+// Throttle activity-event resets to once per second to avoid thrashing the
+// timer on rapid mouse movement.
+const RESET_THROTTLE_MS = 1000;
+
+export function useIdleAutoLock(): void {
+  const { session, signOut } = useAuth();
+  const minutesRef = useRef<AutoLockMinutes>(getAutoLockMinutes());
+  const timerRef = useRef<number | null>(null);
+  const lastResetAtRef = useRef<number>(0);
+
+  // Keep minutesRef live to the setting.
+  useEffect(() => {
+    const unsub = subscribeAutoLockSetting((v) => {
+      minutesRef.current = v;
+      scheduleNext();
+    });
+    return unsub;
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  // Helper: schedule the lock based on the current setting.
+  function scheduleNext(): void {
+    if (timerRef.current !== null) {
+      window.clearTimeout(timerRef.current);
+      timerRef.current = null;
+    }
+    const min = minutesRef.current;
+    if (min === 0) return; // disabled
+    timerRef.current = window.setTimeout(() => {
+      timerRef.current = null;
+      // Fire the lock. signOut wipes local state and navigates to /device
+      // (PIN re-entry screen).
+      void signOut().catch((err) => console.warn('auto-lock signOut failed', err));
+    }, min * 60 * 1000);
+  }
+
+  useEffect(() => {
+    if (!session) return;
+    scheduleNext();
+
+    const onActivity = () => {
+      const now = Date.now();
+      if (now - lastResetAtRef.current < RESET_THROTTLE_MS) return;
+      lastResetAtRef.current = now;
+      scheduleNext();
+    };
+
+    for (const ev of ACTIVITY_EVENTS) {
+      window.addEventListener(ev, onActivity, { passive: true });
+    }
+    return () => {
+      for (const ev of ACTIVITY_EVENTS) {
+        window.removeEventListener(ev, onActivity);
+      }
+      if (timerRef.current !== null) {
+        window.clearTimeout(timerRef.current);
+        timerRef.current = null;
+      }
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [session]);
+}

apps/desktop/src/hooks/useOwnDevices.ts

@@ -0,0 +1,101 @@
+import { useCallback, useEffect, useState } from 'react';
+
+import { type DeviceRecord, listOwnDevices, revokeDevice } from '@chat-app/shared/auth';
+
+import { useAuth } from '../context/AuthContext';
+import { supabase } from '../lib/supabase';
+
+interface State {
+  devices: DeviceRecord[];
+  loading: boolean;
+  error: string | null;
+}
+
+export function useOwnDevices(): {
+  devices: DeviceRecord[];
+  loading: boolean;
+  error: string | null;
+  refresh: () => Promise<void>;
+  revoke: (deviceId: string) => Promise<void>;
+} {
+  const { session } = useAuth();
+  const userId = session?.user.id ?? null;
+  const [state, setState] = useState<State>({ devices: [], loading: true, error: null });
+
+  const refresh = useCallback(async () => {
+    try {
+      setState((s) => ({ ...s, loading: true, error: null }));
+      const list = await listOwnDevices(supabase);
+      setState({ devices: list, loading: false, error: null });
+    } catch (err) {
+      setState((s) => ({
+        ...s,
+        loading: false,
+        error: err instanceof Error ? err.message : 'failed to load devices',
+      }));
+    }
+  }, []);
+
+  useEffect(() => {
+    if (!userId) {
+      setState({ devices: [], loading: false, error: null });
+      return;
+    }
+    void refresh();
+    const channel = supabase
+      .channel('devices:list:' + userId)
+      .on(
+        'postgres_changes',
+        {
+          event: '*',
+          schema: 'public',
+          table: 'devices',
+          filter: 'user_id=eq.' + userId,
+        },
+        () => {
+          void refresh();
+        },
+      )
+      .subscribe();
+    return () => {
+      void supabase.removeChannel(channel);
+    };
+  }, [userId, refresh]);
+
+  const revoke = useCallback(
+    async (deviceId: string) => {
+      // Optimistic: flip `revokedAt` on the row so the "Abgemeldet" badge
+      // appears on the same frame as the click. Capture a snapshot so we
+      // can restore exactly on RPC failure (the realtime subscription's
+      // own UPDATE echo would otherwise reconcile back to "not revoked"
+      // anyway). Skip if the row isn't in our list — nothing to undo.
+      let snapshot: DeviceRecord[] | null = null;
+      const stampedAt = new Date().toISOString();
+      setState((prev) => {
+        if (!prev.devices.some((d) => d.id === deviceId)) return prev;
+        snapshot = prev.devices;
+        return {
+          ...prev,
+          devices: prev.devices.map((d) =>
+            d.id === deviceId ? { ...d, revokedAt: d.revokedAt ?? stampedAt } : d,
+          ),
+        };
+      });
+      try {
+        await revokeDevice(supabase, deviceId);
+        // Skip the eager refresh: the realtime UPDATE on `devices` triggers
+        // refresh() via the subscription and the optimistic row already
+        // shows the badge. Avoids a list flicker between optimistic and
+        // canonical state.
+      } catch (err) {
+        if (snapshot) {
+          setState((prev) => ({ ...prev, devices: snapshot! }));
+        }
+        throw err;
+      }
+    },
+    [],
+  );
+
+  return { devices: state.devices, loading: state.loading, error: state.error, refresh, revoke };
+}

apps/desktop/src/hooks/useSoundboardSync.ts

@@ -0,0 +1,276 @@
+import { useEffect, useRef, useState } from 'react';
+
+import { getCryptoBackend } from '@chat-app/shared/crypto';
+import {
+  decryptSoundEnvelope,
+  downloadSoundCiphertext,
+  encryptSoundBlob,
+  listOwnSounds,
+  type RemoteSound,
+  upsertSound,
+  uploadSoundCiphertext,
+} from '@chat-app/shared/chat';
+
+import { useAuth } from '../context/AuthContext';
+import {
+  deleteRawStoredSound,
+  getRawStoredSound,
+  listSounds,
+  putRawStoredSound,
+  type SoundboardEntry,
+  subscribeSoundboardChanges,
+} from '../lib/soundboardStorage';
+import { supabase } from '../lib/supabase';
+import { cachedUserKey } from '../lib/userIdentity';
+
+export type SyncBadge = 'synced' | 'uploading' | 'downloading' | 'error';
+
+const PUSH_DEBOUNCE_MS = 500;
+const DELETE_GRACE_MS = 5000;
+
+function storagePathFor(userId: string, soundId: string): string {
+  return userId + '/' + soundId + '.bin';
+}
+
+export function useSoundboardSync(): {
+  badges: Map<string, SyncBadge>;
+  initialPullDone: boolean;
+} {
+  const { session } = useAuth();
+  const userId = session?.user.id ?? null;
+  const [badges, setBadges] = useState<Map<string, SyncBadge>>(new Map());
+  const [initialPullDone, setInitialPullDone] = useState(false);
+  const debounceRef = useRef<number | null>(null);
+
+  function setBadge(id: string, badge: SyncBadge): void {
+    setBadges((cur) => {
+      const next = new Map(cur);
+      next.set(id, badge);
+      return next;
+    });
+  }
+
+  useEffect(() => {
+    if (!userId) {
+      setInitialPullDone(false);
+      setBadges(new Map());
+      return;
+    }
+    let cancelled = false;
+    let teardown: (() => void) | null = null;
+
+    const init = async () => {
+      const priv = await cachedUserKey(userId);
+      if (!priv) return;
+      const pub = getCryptoBackend().scalarMultBase(priv);
+
+      try {
+        await runDiff(userId, priv, pub);
+      } catch (err) {
+        console.error('soundboard initial diff failed', err);
+      }
+      if (cancelled) return;
+      setInitialPullDone(true);
+
+      const unsubLocal = subscribeSoundboardChanges(() => {
+        if (debounceRef.current !== null) window.clearTimeout(debounceRef.current);
+        debounceRef.current = window.setTimeout(() => {
+          debounceRef.current = null;
+          void runDiff(userId, priv, pub).catch((err) => {
+            console.error('soundboard push diff failed', err);
+          });
+        }, PUSH_DEBOUNCE_MS);
+      });
+
+      const channel = supabase
+        .channel('soundboards:' + userId)
+        .on(
+          'postgres_changes',
+          {
+            event: '*',
+            schema: 'public',
+            table: 'user_soundboards',
+            filter: 'user_id=eq.' + userId,
+          },
+          () => {
+            void runDiff(userId, priv, pub).catch((err) => {
+              console.error('soundboard realtime pull failed', err);
+            });
+          },
+        )
+        .subscribe();
+
+      teardown = () => {
+        unsubLocal();
+        void supabase.removeChannel(channel);
+        if (debounceRef.current !== null) {
+          window.clearTimeout(debounceRef.current);
+          debounceRef.current = null;
+        }
+      };
+    };
+
+    void init();
+    return () => {
+      cancelled = true;
+      teardown?.();
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [userId]);
+
+  async function runDiff(uid: string, priv: Uint8Array, pub: Uint8Array): Promise<void> {
+    const [localList, remoteList] = await Promise.all([
+      listSounds(),
+      listOwnSounds(supabase),
+    ]);
+    const remoteById = new Map<string, RemoteSound>();
+    for (const r of remoteList) remoteById.set(r.id, r);
+    const localById = new Map<string, SoundboardEntry>();
+    for (const l of localList) localById.set(l.id, l);
+
+    // Push pass
+    for (const local of localList) {
+      const remote = remoteById.get(local.id);
+      const localIso = new Date(local.updatedAt).toISOString();
+      if (!remote) {
+        await uploadAndUpsert(local, uid, priv, pub, localIso);
+      } else {
+        const remoteMs = Date.parse(remote.updatedAt);
+        if (local.updatedAt > remoteMs) {
+          await upsertMetadataOnly(local, remote, localIso);
+        }
+      }
+    }
+
+    // Pull pass
+    for (const remote of remoteList) {
+      const local = localById.get(remote.id);
+      const remoteMs = Date.parse(remote.updatedAt);
+      if (!local) {
+        await pullAndStore(remote, priv, pub);
+      } else if (remoteMs > local.updatedAt) {
+        const stored = await getRawStoredSound(remote.id);
+        if (stored) {
+          await putRawStoredSound({
+            ...stored,
+            name: remote.name,
+            mime: remote.mime,
+            size: remote.size,
+            category: remote.category,
+            hotkey: remote.hotkey,
+            gain: remote.gain,
+            order: remote.sortOrder,
+            updatedAt: remoteMs,
+          });
+          setBadge(remote.id, 'synced');
+        }
+      } else {
+        setBadge(remote.id, 'synced');
+      }
+    }
+
+    // Remote-absence → local delete (with grace window for fresh adds).
+    const now = Date.now();
+    for (const local of localList) {
+      if (!remoteById.has(local.id) && now - local.updatedAt > DELETE_GRACE_MS) {
+        await deleteRawStoredSound(local.id);
+      }
+    }
+  }
+
+  async function uploadAndUpsert(
+    local: SoundboardEntry,
+    uid: string,
+    priv: Uint8Array,
+    pub: Uint8Array,
+    localIso: string,
+  ): Promise<void> {
+    setBadge(local.id, 'uploading');
+    try {
+      const stored = await getRawStoredSound(local.id);
+      if (!stored) return;
+      const ciphertext = await encryptSoundBlob(stored.blob, pub, priv);
+      const path = storagePathFor(uid, local.id);
+      await uploadSoundCiphertext(supabase, path, ciphertext);
+      await upsertSound(supabase, {
+        id: local.id,
+        name: local.name,
+        mime: local.mime,
+        size: local.size,
+        category: local.category,
+        hotkey: local.hotkey,
+        gain: local.gain,
+        sortOrder: local.order,
+        storagePath: path,
+        updatedAtIso: localIso,
+      });
+      setBadge(local.id, 'synced');
+    } catch (err) {
+      console.error('soundboard upload failed', err);
+      setBadge(local.id, 'error');
+    }
+  }
+
+  async function upsertMetadataOnly(
+    local: SoundboardEntry,
+    remote: RemoteSound,
+    localIso: string,
+  ): Promise<void> {
+    setBadge(local.id, 'uploading');
+    try {
+      await upsertSound(supabase, {
+        id: local.id,
+        name: local.name,
+        mime: local.mime,
+        size: local.size,
+        category: local.category,
+        hotkey: local.hotkey,
+        gain: local.gain,
+        sortOrder: local.order,
+        storagePath: remote.storagePath,
+        updatedAtIso: localIso,
+      });
+      setBadge(local.id, 'synced');
+    } catch (err) {
+      console.error('soundboard metadata upload failed', err);
+      setBadge(local.id, 'error');
+    }
+  }
+
+  async function pullAndStore(
+    remote: RemoteSound,
+    priv: Uint8Array,
+    pub: Uint8Array,
+  ): Promise<void> {
+    setBadge(remote.id, 'downloading');
+    try {
+      const envelope = await downloadSoundCiphertext(supabase, remote.storagePath);
+      const plain = await decryptSoundEnvelope(envelope, pub, priv);
+      // Copy into a fresh ArrayBuffer so Blob accepts it across TS lib variants
+      // (mirrors the pattern in @chat-app/shared/chat/attachments.ts).
+      const copy = new Uint8Array(plain.byteLength);
+      copy.set(plain);
+      const blob = new Blob([copy.buffer], { type: remote.mime });
+      const ms = Date.parse(remote.updatedAt);
+      await putRawStoredSound({
+        id: remote.id,
+        name: remote.name,
+        mime: remote.mime,
+        size: remote.size,
+        category: remote.category,
+        hotkey: remote.hotkey,
+        gain: remote.gain,
+        order: remote.sortOrder,
+        createdAt: Date.parse(remote.createdAt),
+        updatedAt: ms,
+        blob,
+      });
+      setBadge(remote.id, 'synced');
+    } catch (err) {
+      console.error('soundboard pull failed', err);
+      setBadge(remote.id, 'error');
+    }
+  }
+
+  return { badges, initialPullDone };
+}

apps/desktop/src/hooks/useWatchSession.ts

@@ -0,0 +1,145 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+
+import {
+  endWatchSession,
+  getWatchSession,
+  updateWatchSessionState,
+  type WatchSession,
+  type WatchSessionState,
+} from '@chat-app/shared/chat';
+
+import { supabase } from '../lib/supabase';
+
+const PUSH_THROTTLE_MS = 500;
+
+export function useWatchSession(sessionId: string | null): {
+  session: WatchSession | null;
+  loading: boolean;
+  error: string | null;
+  pushState: (state: WatchSessionState) => void;
+  endSession: () => Promise<void>;
+} {
+  const [session, setSession] = useState<WatchSession | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const pendingRef = useRef<WatchSessionState | null>(null);
+  const lastPushAtRef = useRef<number>(0);
+  const pushTimerRef = useRef<number | null>(null);
+
+  useEffect(() => {
+    if (!sessionId) {
+      setSession(null);
+      setLoading(false);
+      setError(null);
+      return;
+    }
+    let cancelled = false;
+    void (async () => {
+      try {
+        setLoading(true);
+        setError(null);
+        const fresh = await getWatchSession(supabase, sessionId);
+        if (!cancelled) {
+          setSession(fresh);
+          setLoading(false);
+        }
+      } catch (err) {
+        if (!cancelled) {
+          setLoading(false);
+          setError(err instanceof Error ? err.message : 'failed to load session');
+        }
+      }
+    })();
+
+    const channel = supabase
+      .channel('watch_session:' + sessionId)
+      .on(
+        'postgres_changes',
+        {
+          event: 'UPDATE',
+          schema: 'public',
+          table: 'conversation_watch_sessions',
+          filter: 'id=eq.' + sessionId,
+        },
+        (payload) => {
+          const row = payload.new as {
+            id?: string;
+            ended_at?: string | null;
+            current_state?: unknown;
+          } | null;
+          if (!row?.id) return;
+          const raw = (row.current_state ?? {}) as Partial<{
+            playing: boolean;
+            position_seconds: number;
+            updated_at_ms: number;
+          }>;
+          setSession((cur) => {
+            if (!cur) return cur;
+            return {
+              ...cur,
+              endedAt: row.ended_at ?? null,
+              currentState: {
+                playing: typeof raw.playing === 'boolean' ? raw.playing : cur.currentState.playing,
+                positionSeconds:
+                  typeof raw.position_seconds === 'number'
+                    ? raw.position_seconds
+                    : cur.currentState.positionSeconds,
+                updatedAtMs:
+                  typeof raw.updated_at_ms === 'number'
+                    ? raw.updated_at_ms
+                    : cur.currentState.updatedAtMs,
+              },
+            };
+          });
+        },
+      )
+      .subscribe();
+
+    return () => {
+      cancelled = true;
+      void supabase.removeChannel(channel);
+      if (pushTimerRef.current !== null) {
+        window.clearTimeout(pushTimerRef.current);
+        pushTimerRef.current = null;
+      }
+    };
+  }, [sessionId]);
+
+  // Throttled writer: keeps the latest state in pendingRef; fires at most
+  // once per PUSH_THROTTLE_MS. Trailing-edge push guarantees the final
+  // state is always sent even when a rapid burst stops before the leading-
+  // edge timeout expires.
+  const pushState = useCallback((state: WatchSessionState) => {
+    if (!sessionId) return;
+    pendingRef.current = state;
+    const now = Date.now();
+    const elapsed = now - lastPushAtRef.current;
+    if (elapsed >= PUSH_THROTTLE_MS) {
+      lastPushAtRef.current = now;
+      const toPush = pendingRef.current;
+      pendingRef.current = null;
+      void updateWatchSessionState(supabase, sessionId, toPush).catch((err) => {
+        console.warn('updateWatchSessionState failed', err);
+      });
+      return;
+    }
+    if (pushTimerRef.current !== null) window.clearTimeout(pushTimerRef.current);
+    pushTimerRef.current = window.setTimeout(() => {
+      pushTimerRef.current = null;
+      const toPush = pendingRef.current;
+      if (!toPush) return;
+      pendingRef.current = null;
+      lastPushAtRef.current = Date.now();
+      void updateWatchSessionState(supabase, sessionId, toPush).catch((err) => {
+        console.warn('updateWatchSessionState trailing failed', err);
+      });
+    }, PUSH_THROTTLE_MS - elapsed);
+  }, [sessionId]);
+
+  const endSession = useCallback(async () => {
+    if (!sessionId) return;
+    await endWatchSession(supabase, sessionId);
+  }, [sessionId]);
+
+  return { session, loading, error, pushState, endSession };
+}

apps/desktop/src/hooks/useWhiteboardStrokes.ts

@@ -0,0 +1,130 @@
+import { useCallback, useEffect, useState } from 'react';
+
+import {
+  clearWhiteboardStrokes,
+  insertWhiteboardStroke,
+  listWhiteboardStrokes,
+  type WhiteboardStroke,
+} from '@chat-app/shared/chat';
+
+import { supabase } from '../lib/supabase';
+
+interface State {
+  strokes: WhiteboardStroke[];
+  loading: boolean;
+  error: string | null;
+}
+
+export function useWhiteboardStrokes(whiteboardId: string | null): {
+  strokes: WhiteboardStroke[];
+  loading: boolean;
+  error: string | null;
+  insertStroke: (strokeJson: unknown) => Promise<void>;
+  clearAll: () => Promise<void>;
+} {
+  const [state, setState] = useState<State>({ strokes: [], loading: true, error: null });
+
+  useEffect(() => {
+    if (!whiteboardId) {
+      setState({ strokes: [], loading: false, error: null });
+      return;
+    }
+    let cancelled = false;
+    void (async () => {
+      try {
+        setState((s) => ({ ...s, loading: true, error: null }));
+        const list = await listWhiteboardStrokes(supabase, whiteboardId);
+        if (!cancelled) setState({ strokes: list, loading: false, error: null });
+      } catch (err) {
+        if (!cancelled) {
+          setState({
+            strokes: [],
+            loading: false,
+            error: err instanceof Error ? err.message : 'failed to load strokes',
+          });
+        }
+      }
+    })();
+    const channel = supabase
+      .channel('whiteboard:' + whiteboardId)
+      .on(
+        'postgres_changes',
+        {
+          event: 'INSERT',
+          schema: 'public',
+          table: 'whiteboard_strokes',
+          filter: 'whiteboard_id=eq.' + whiteboardId,
+        },
+        (payload) => {
+          const row = payload.new as {
+            id?: string;
+            whiteboard_id?: string;
+            author_user_id?: string;
+            stroke_json?: unknown;
+            created_at?: string;
+          } | null;
+          if (!row?.id || !row.whiteboard_id || !row.author_user_id || !row.created_at) return;
+          const next: WhiteboardStroke = {
+            id: row.id,
+            whiteboardId: row.whiteboard_id,
+            authorUserId: row.author_user_id,
+            strokeJson: row.stroke_json,
+            createdAt: row.created_at,
+          };
+          setState((s) => {
+            if (s.strokes.some((x) => x.id === next.id)) return s;
+            return { ...s, strokes: [...s.strokes, next] };
+          });
+        },
+      )
+      .on(
+        'postgres_changes',
+        {
+          event: 'DELETE',
+          schema: 'public',
+          table: 'whiteboard_strokes',
+          filter: 'whiteboard_id=eq.' + whiteboardId,
+        },
+        () => {
+          // Bulk delete via "Clear all" — drop everything; future inserts
+          // come back via the INSERT branch above.
+          setState((s) => ({ ...s, strokes: [] }));
+        },
+      )
+      .subscribe();
+    return () => {
+      cancelled = true;
+      void supabase.removeChannel(channel);
+    };
+  }, [whiteboardId]);
+
+  const insertStroke = useCallback(
+    async (strokeJson: unknown) => {
+      if (!whiteboardId) return;
+      try {
+        await insertWhiteboardStroke(supabase, { whiteboardId, strokeJson });
+        // No optimistic append — realtime echoes the row back in <150ms.
+      } catch (err) {
+        console.error('insertWhiteboardStroke failed', err);
+        setState((s) => ({
+          ...s,
+          error: err instanceof Error ? err.message : 'stroke insert failed',
+        }));
+      }
+    },
+    [whiteboardId],
+  );
+
+  const clearAll = useCallback(async () => {
+    if (!whiteboardId) return;
+    await clearWhiteboardStrokes(supabase, whiteboardId);
+  }, [whiteboardId]);
+
+  return {
+    strokes: state.strokes,
+    loading: state.loading,
+    error: state.error,
+    insertStroke,
+    clearAll,
+  };
+}

apps/desktop/src/lib/autoLockSettings.ts

@@ -0,0 +1,43 @@
+// Per-install setting for PIN-idle-auto-lock. 0 = disabled.
+// Values match the dropdown options (5/15/30/60 minutes).
+
+const KEY = 'chatapp.autoLockMinutes.v1';
+
+export type AutoLockMinutes = 0 | 5 | 15 | 30 | 60;
+
+const VALID: AutoLockMinutes[] = [0, 5, 15, 30, 60];
+
+export function getAutoLockMinutes(): AutoLockMinutes {
+  try {
+    const raw = window.localStorage.getItem(KEY);
+    if (!raw) return 0;
+    const n = Number(raw);
+    if (VALID.includes(n as AutoLockMinutes)) return n as AutoLockMinutes;
+    return 0;
+  } catch {
+    return 0;
+  }
+}
+
+type Listener = (value: AutoLockMinutes) => void;
+const listeners = new Set<Listener>();
+
+export function subscribeAutoLockSetting(l: Listener): () => void {
+  listeners.add(l);
+  return () => listeners.delete(l);
+}
+
+export function notifyAutoLockChanged(value: AutoLockMinutes): void {
+  for (const l of listeners) {
+    try { l(value); } catch (err) { console.warn(err); }
+  }
+}
+
+export function setAutoLockMinutes(value: AutoLockMinutes): void {
+  try {
+    window.localStorage.setItem(KEY, String(value));
+  } catch {
+    /* quota */
+  }
+  notifyAutoLockChanged(value);
+}

apps/desktop/src/lib/conversationFeatures.ts

@@ -4,6 +4,9 @@ import {
   type AttachmentHandle,
   type DecryptedMessage,
   type PollOption,
+  type WhiteboardPayload,
+  type WatchTogetherPayload,
+  type GamePayload,
 } from '@chat-app/shared/chat';
 
 export type AttachmentBucket = 'media' | 'audio' | 'files';
@@ -97,6 +100,34 @@ export function createPollPayload(question: string, optionTexts: string[]): stri
   });
 }
 
+export function createWhiteboardPayload(whiteboardId: string): string {
+  const payload: WhiteboardPayload = {
+    v: 1,
+    type: 'whiteboard',
+    whiteboard_id: whiteboardId,
+  };
+  return serializeMessagePayload(payload);
+}
+
+export function createWatchTogetherPayload(sessionId: string): string {
+  const payload: WatchTogetherPayload = {
+    v: 1,
+    type: 'watch_together',
+    session_id: sessionId,
+  };
+  return serializeMessagePayload(payload);
+}
+
+export function createGamePayload(gameId: string, gameType: 'ttt' | 'c4'): string {
+  const payload: GamePayload = {
+    v: 1,
+    type: 'game',
+    game_id: gameId,
+    game_type: gameType,
+  };
+  return serializeMessagePayload(payload);
+}
+
 export function summarizePollVotes(
   options: PollOption[],
   reactions: ReactionSummaryInput[],

apps/desktop/src/lib/cryptoBackend.ts

@@ -25,5 +25,13 @@ export async function createLibsodiumBackend(): Promise<CryptoBackend> {
       s.crypto_box_open_easy(ciphertext, nonce, senderPublicKey, recipientPrivateKey),
     secretbox: (plaintext, nonce, key) => s.crypto_secretbox_easy(plaintext, nonce, key),
     secretboxOpen: (ciphertext, nonce, key) => s.crypto_secretbox_open_easy(ciphertext, nonce, key),
+    pwhashConsts: {
+      OPSLIMIT_MODERATE: s.crypto_pwhash_OPSLIMIT_MODERATE,
+      MEMLIMIT_MODERATE: s.crypto_pwhash_MEMLIMIT_MODERATE,
+      ALG_ARGON2ID13: s.crypto_pwhash_ALG_ARGON2ID13,
+    },
+    pwhash: (outLen, password, salt, opslimit, memlimit, alg) =>
+      s.crypto_pwhash(outLen, password, salt, opslimit, memlimit, alg),
+    scalarMultBase: (priv) => s.crypto_scalarmult_base(priv),
   };
 }

apps/desktop/src/lib/cryptoWorker.ts

@@ -0,0 +1,73 @@
+// Main-thread wrapper around the crypto Web Worker (Argon2id pwhash +
+// sealed user-key open). Each unlock attempt spawns a fresh one-shot worker
+// — workers are cheap and the pwhash is a one-time cost per login, so we
+// avoid the bookkeeping needed for a persistent request queue.
+//
+// Falls back to inline (main-thread) `openUserKey` when the `Worker`
+// constructor is unavailable (e.g. vitest's jsdom environment, strict CSPs).
+// The fallback path is identical in semantics to the worker path; the only
+// difference is whether it blocks the main thread.
+//
+// Why not a long-lived worker? The KDF cost dwarfs the spawn cost (~1-2 s
+// vs. a few ms), and PIN-unlock happens at most once per session. Keeping a
+// worker resident would also require a request-id correlation map which the
+// decrypt.worker uses (because per-message decrypts are high-volume).
+
+import { openUserKey } from '@chat-app/shared/crypto';
+
+import type {
+  OpenUserKeyInput,
+  OpenUserKeyResult,
+} from '../workers/crypto.worker';
+
+type WorkerResponse =
+  | { ok: true; result: OpenUserKeyResult }
+  | { ok: false; error: string };
+
+export type { OpenUserKeyInput, OpenUserKeyResult };
+
+export async function openUserKeyInWorker(
+  input: OpenUserKeyInput,
+): Promise<OpenUserKeyResult> {
+  const worker = new Worker(
+    new URL('../workers/crypto.worker.ts', import.meta.url),
+    { type: 'module' },
+  );
+  try {
+    return await new Promise<OpenUserKeyResult>((resolve, reject) => {
+      worker.addEventListener('message', (ev: MessageEvent<WorkerResponse>) => {
+        const msg = ev.data;
+        if (msg && msg.ok) resolve(msg.result);
+        else reject(new Error(msg?.error ?? 'crypto worker returned malformed response'));
+      });
+      worker.addEventListener('error', (ev: ErrorEvent) => {
+        reject(new Error(ev.message || 'crypto worker error'));
+      });
+      worker.postMessage({ op: 'openUserKey', input });
+    });
+  } finally {
+    worker.terminate();
+  }
+}
+
+// Public entry point: route through the worker when possible, fall back to
+// the synchronous-on-main-thread path otherwise. Callers should prefer this
+// over importing `openUserKey` directly so we get the worker speedup
+// everywhere it's available.
+export async function openUserKeyMaybeWorker(
+  input: OpenUserKeyInput,
+): Promise<Uint8Array> {
+  if (typeof Worker === 'undefined') {
+    return openUserKey(input);
+  }
+  try {
+    const result = await openUserKeyInWorker(input);
+    return result.privateKey;
+  } catch (err) {
+    // If the worker spawn or message round-trip fails (e.g. CSP blocks
+    // module workers in some packaging modes), fall back to inline so the
+    // unlock still succeeds — just with a brief main-thread hitch.
+    console.warn('[cryptoWorker] worker path failed, falling back to inline', err);
+    return openUserKey(input);
+  }
+}

apps/desktop/src/lib/deviceRowId.ts

@@ -0,0 +1,30 @@
+// localStorage key for "the devices.id row that belongs to THIS install".
+// Reset on memory-wipe (NOT preserved) — a wiped install is conceptually a
+// fresh install, so registering a new row is correct.
+
+const KEY = 'chatapp.deviceRowId.v1';
+
+export function getDeviceRowId(): string | null {
+  try {
+    const v = window.localStorage.getItem(KEY);
+    return v && v.length > 0 ? v : null;
+  } catch {
+    return null;
+  }
+}
+
+export function setDeviceRowId(id: string): void {
+  try {
+    window.localStorage.setItem(KEY, id);
+  } catch {
+    /* quota */
+  }
+}
+
+export function clearDeviceRowId(): void {
+  try {
+    window.localStorage.removeItem(KEY);
+  } catch {
+    /* no-op */
+  }
+}

apps/desktop/src/lib/friendNicknames.ts

@@ -0,0 +1,64 @@
+import { useSyncExternalStore } from 'react';
+
+// Local-only friend nickname overrides. Stored in localStorage keyed by the
+// peer's user-id. Empty/missing value = use the real display name.
+// Local-only by design — friends never see your nickname for them.
+
+const STORAGE_KEY = 'chatapp.friendNicknames.v1';
+
+let cache: Record<string, string> | null = null;
+const listeners = new Set<() => void>();
+
+function load(): Record<string, string> {
+  if (cache) return cache;
+  try {
+    const raw = window.localStorage.getItem(STORAGE_KEY);
+    if (!raw) { cache = {}; return cache; }
+    const parsed = JSON.parse(raw) as unknown;
+    if (parsed && typeof parsed === 'object') {
+      cache = {};
+      for (const [k, v] of Object.entries(parsed as Record<string, unknown>)) {
+        if (typeof v === 'string' && v.trim().length > 0) cache[k] = v;
+      }
+      return cache;
+    }
+  } catch { /* corrupted; fall through */ }
+  cache = {};
+  return cache;
+}
+
+function persist(): void {
+  try { window.localStorage.setItem(STORAGE_KEY, JSON.stringify(cache ?? {})); }
+  catch { /* quota / private mode */ }
+  for (const l of listeners) l();
+}
+
+export function getNickname(userId: string): string | null {
+  return load()[userId] ?? null;
+}
+
+export function setNickname(userId: string, nickname: string | null): void {
+  const store = load();
+  const trimmed = nickname?.trim() ?? '';
+  if (trimmed.length === 0) {
+    if (!(userId in store)) return;
+    delete store[userId];
+  } else {
+    if (store[userId] === trimmed) return;
+    store[userId] = trimmed;
+  }
+  persist();
+}
+
+// Reactive hook: returns the current nickname for a user, or `fallback`
+// when no nickname is set. Re-renders when ANY nickname changes (cheap,
+// the set is small).
+export function useNickname(userId: string | null | undefined, fallback: string): string {
+  const subscribe = (cb: () => void) => {
+    listeners.add(cb);
+    return () => { listeners.delete(cb); };
+  };
+  const getSnapshot = () => (userId ? getNickname(userId) : null);
+  const nickname = useSyncExternalStore(subscribe, getSnapshot, getSnapshot);
+  return nickname ?? fallback;
+}

apps/desktop/src/lib/imageCompress.ts

@@ -55,3 +55,51 @@ function renameToWebp(original: string): string {
 export async function compressImages(files: File[]): Promise<File[]> {
   return Promise.all(files.map((f) => compressImage(f)));
 }
+
+// Bandwidth threshold for thumb generation. Below ~50KB the WebP overhead
+// of a fresh re-encode can exceed the original; not worth a second upload.
+const THUMB_SKIP_BELOW_BYTES = 50 * 1024;
+const THUMB_MAX_DIM = 320;
+const THUMB_QUALITY = 0.7;
+// Animated formats lose motion when redrawn onto a Canvas, so we skip them
+// and let the receiver render the full file. GIF is the dominant case; the
+// rest stay too (apng/animated-webp).
+const THUMB_ANIMATED_MIME = /^image\/(gif|apng)$/;
+
+// Generates a small WebP preview thumb (max 320×320) from an image file.
+// Used by the send path so each image attachment can ship a tiny inline
+// preview alongside the encrypted full blob. Returns `null` when:
+//  - the input isn't an image,
+//  - the input is animated (GIF/APNG — would lose motion),
+//  - the input is already small enough that a thumb wouldn't save bandwidth,
+//  - OffscreenCanvas / createImageBitmap aren't available, or
+//  - decode/encode threw (corrupt input).
+// The caller treats `null` as "skip thumb" and uploads only the full blob.
+export async function generateWebPThumb(
+  file: File,
+  maxDim: number = THUMB_MAX_DIM,
+): Promise<Blob | null> {
+  if (!file.type.startsWith('image/')) return null;
+  if (THUMB_ANIMATED_MIME.test(file.type)) return null;
+  if (file.size < THUMB_SKIP_BELOW_BYTES) return null;
+  if (typeof createImageBitmap !== 'function') return null;
+  if (typeof OffscreenCanvas !== 'function') return null;
+  try {
+    const bitmap = await createImageBitmap(file);
+    const ratio = Math.min(maxDim / bitmap.width, maxDim / bitmap.height, 1);
+    const w = Math.max(1, Math.round(bitmap.width * ratio));
+    const h = Math.max(1, Math.round(bitmap.height * ratio));
+    const canvas = new OffscreenCanvas(w, h);
+    const ctx = canvas.getContext('2d');
+    if (!ctx) {
+      bitmap.close();
+      return null;
+    }
+    ctx.drawImage(bitmap, 0, 0, w, h);
+    bitmap.close();
+    return await canvas.convertToBlob({ type: 'image/webp', quality: THUMB_QUALITY });
+  } catch (err: unknown) {
+    console.warn('generateWebPThumb failed', err);
+    return null;
+  }
+}

apps/desktop/src/lib/memoryWipe.ts

@@ -0,0 +1,56 @@
+import { clearConvKeyCache } from '@chat-app/shared/chat';
+
+import { devLocalSecretStore } from './secretStore';
+
+// Aggressively scrub local crypto + chat caches on sign-out (and on
+// app-close if the user opted in). Preserves things that aren't sensitive
+// and would be annoying to lose (theme, locale, install-id).
+//
+// We can't enumerate IndexedDB names without async + the indexedDB API,
+// so we list the ones we know about explicitly. Adding a new local store
+// later? Append to LOCAL_DBS.
+
+const LOCAL_DBS = ['soundboard', 'message-cache', 'chatapp-attachments'];
+const PRESERVE_LOCAL_STORAGE = new Set([
+  'chatapp.theme',
+  'chatapp.locale',
+  'chatapp.installId',
+  'chatapp.wipeOnClose.v1',
+  'chatapp.autoLockMinutes.v1',
+  'i18nextLng',
+]);
+
+export async function wipeLocalState(userId: string | null): Promise<void> {
+  // 1. Per-conversation key cache (in-memory).
+  try { clearConvKeyCache(); } catch { /* never throws but be defensive */ }
+
+  // 2. Stronghold / secret-store: drop the user-priv blob for this user.
+  if (userId) {
+    try { await devLocalSecretStore.removeSecret('chatapp.userpriv.' + userId); }
+    catch (err) { console.warn('[wipe] userpriv remove failed', err); }
+  }
+
+  // 3. localStorage — preserve only the explicit whitelist.
+  try {
+    const keysToDrop: string[] = [];
+    for (let i = 0; i < window.localStorage.length; i++) {
+      const k = window.localStorage.key(i);
+      if (k && !PRESERVE_LOCAL_STORAGE.has(k)) keysToDrop.push(k);
+    }
+    for (const k of keysToDrop) window.localStorage.removeItem(k);
+  } catch (err) { console.warn('[wipe] localStorage clear failed', err); }
+
+  // 4. sessionStorage — always full.
+  try { window.sessionStorage.clear(); } catch { /* ignored */ }
+
+  // 5. IndexedDB — delete known databases. Resolves even when blocked so
+  // we don't hang sign-out forever.
+  await Promise.allSettled(LOCAL_DBS.map((name) => new Promise<void>((resolve) => {
+    try {
+      const req = window.indexedDB.deleteDatabase(name);
+      req.onsuccess = () => resolve();
+      req.onerror = () => resolve();
+      req.onblocked = () => resolve();
+    } catch { resolve(); }
+  })));
+}

apps/desktop/src/lib/memoryWipeSettings.ts

@@ -0,0 +1,24 @@
+// Persisted toggle for the "wipe local caches on app close" feature.
+// Read by SecurityCenter (UI) and AuthContext (renderer-side IPC handler).
+//
+// Stored in localStorage so the preference survives sessions without
+// touching the secret-store or SQLite. The key is on the preserve
+// whitelist in lib/memoryWipe.ts so a sign-out wipe (or a closing wipe)
+// doesn't blow away the user's own preference.
+const KEY = 'chatapp.wipeOnClose.v1';
+
+export function isWipeOnCloseEnabled(): boolean {
+  try {
+    return window.localStorage.getItem(KEY) === '1';
+  } catch {
+    return false;
+  }
+}
+
+export function setWipeOnClose(enabled: boolean): void {
+  try {
+    window.localStorage.setItem(KEY, enabled ? '1' : '0');
+  } catch {
+    /* ignored */
+  }
+}

apps/desktop/src/lib/soundboardStorage.ts

@@ -369,3 +369,52 @@ export async function isHotkeyTaken(
   }
   return false;
 }
+
+// --- Sync-engine bypass helpers ------------------------------------------
+// Used by useSoundboardSync to write/delete IndexedDB rows without firing
+// notifyChange — pulls and remote-driven deletes are not "edits". If they
+// triggered notifyChange the engine would loop:
+//   push debounce → upsert → realtime → pull → notifyChange → push debounce → ...
+
+export async function putRawStoredSound(stored: {
+  id: string;
+  name: string;
+  mime: string;
+  size: number;
+  category: string | null;
+  hotkey: string | null;
+  gain: number;
+  order: number;
+  createdAt: number;
+  updatedAt: number;
+  blob: Blob;
+}): Promise<void> {
+  await tx(SOUNDS_STORE, 'readwrite', (s) => s.put(stored));
+}
+
+export async function deleteRawStoredSound(id: string): Promise<void> {
+  await tx(SOUNDS_STORE, 'readwrite', (s) => s.delete(id));
+}
+
+export async function getRawStoredSound(id: string): Promise<{
+  id: string;
+  name: string;
+  mime: string;
+  size: number;
+  category: string | null;
+  hotkey: string | null;
+  gain: number;
+  order: number;
+  createdAt: number;
+  updatedAt: number;
+  blob: Blob;
+} | null> {
+  const db = await openDb();
+  return new Promise((resolve, reject) => {
+    const t = db.transaction(SOUNDS_STORE, 'readonly');
+    const s = t.objectStore(SOUNDS_STORE);
+    const req = s.get(id);
+    req.onsuccess = () => resolve((req.result as any) ?? null);
+    req.onerror = () => reject(req.error);
+  });
+}

apps/desktop/src/lib/tenor.ts

@@ -0,0 +1,115 @@
+// GIPHY v1 client — Google closed Tenor to new API clients in Jan 2026, so
+// the picker uses GIPHY's Developer API instead. Provision a free key at
+// https://developers.giphy.com/dashboard/ and expose it via the renderer
+// env var VITE_GIPHY_API_KEY (e.g. in apps/desktop/.env.local). When unset,
+// every call throws — the picker degrades to a friendly
+// "GIFs sind nicht konfiguriert" message via the consumer's catch.
+//
+// The file is still named `tenor.ts` for import-path stability; rename later
+// if it bothers anyone.
+
+const ENDPOINT = 'https://api.giphy.com/v1/gifs';
+const RECENT_KEY = 'chatapp.gifRecent.v1';
+const RECENT_MAX = 24;
+const API_KEY = (
+  (import.meta as unknown as { env?: { VITE_GIPHY_API_KEY?: string } }).env
+    ?.VITE_GIPHY_API_KEY ?? ''
+).trim();
+
+export interface GifResult {
+  id: string;
+  // Animated full-size URL (typically <2 MB).
+  url: string;
+  // Small preview shown in the picker grid.
+  previewUrl: string;
+  width: number;
+  height: number;
+  description: string;
+}
+
+interface GiphyImage {
+  url?: string;
+  width?: string;
+  height?: string;
+}
+
+interface GiphyResult {
+  id: string;
+  title?: string;
+  images?: {
+    original?: GiphyImage;
+    fixed_height?: GiphyImage;
+    fixed_height_small?: GiphyImage;
+    preview_gif?: GiphyImage;
+  };
+}
+
+function mapResult(r: GiphyResult): GifResult | null {
+  const full = r.images?.original ?? r.images?.fixed_height;
+  const preview =
+    r.images?.fixed_height_small ?? r.images?.preview_gif ?? r.images?.fixed_height ?? full;
+  if (!full?.url || !preview?.url) return null;
+  return {
+    id: r.id,
+    url: full.url,
+    previewUrl: preview.url,
+    width: full.width ? Number(full.width) : 0,
+    height: full.height ? Number(full.height) : 0,
+    description: r.title ?? '',
+  };
+}
+
+async function fetchGiphy(path: string, params: Record<string, string>): Promise<GifResult[]> {
+  if (!API_KEY) {
+    throw new Error('giphy_api_key_missing');
+  }
+  const search = new URLSearchParams({ api_key: API_KEY, rating: 'pg-13', ...params });
+  const res = await fetch(`${ENDPOINT}/${path}?${search.toString()}`);
+  if (!res.ok) throw new Error('giphy http ' + res.status);
+  const json = (await res.json()) as { data?: GiphyResult[] };
+  return (json.data ?? []).map(mapResult).filter((x): x is GifResult => x !== null);
+}
+
+export function isGifProviderConfigured(): boolean {
+  return API_KEY.length > 0;
+}
+
+// Back-compat alias for the original Tenor function name. New code should
+// use isGifProviderConfigured.
+export const isTenorConfigured = isGifProviderConfigured;
+
+export async function searchGifs(query: string, locale: string = 'de'): Promise<GifResult[]> {
+  if (!query.trim()) return featuredGifs(locale);
+  return fetchGiphy('search', { q: query, limit: '30', lang: locale });
+}
+
+export async function featuredGifs(_locale: string = 'de'): Promise<GifResult[]> {
+  return fetchGiphy('trending', { limit: '30' });
+}
+
+export function getRecentGifs(): GifResult[] {
+  try {
+    const raw = window.localStorage.getItem(RECENT_KEY);
+    if (!raw) return [];
+    const parsed = JSON.parse(raw) as unknown;
+    if (!Array.isArray(parsed)) return [];
+    return parsed.filter(
+      (x): x is GifResult =>
+        x != null &&
+        typeof x === 'object' &&
+        typeof (x as GifResult).url === 'string',
+    );
+  } catch {
+    return [];
+  }
+}
+
+export function rememberRecentGif(gif: GifResult): void {
+  const current = getRecentGifs().filter((g) => g.id !== gif.id);
+  const next = [gif, ...current].slice(0, RECENT_MAX);
+  try {
+    window.localStorage.setItem(RECENT_KEY, JSON.stringify(next));
+  } catch {
+    /* quota */
+  }
+}

apps/desktop/src/lib/useConversationMessages.ts

@@ -16,6 +16,7 @@ import { bytesToPgHex, pgBytesToBytes } from '@chat-app/shared/supabase';
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 
 import { decryptBatch as decryptBatchWorker } from './decryptWorker';
+import { generateWebPThumb } from './imageCompress';
 import {
   loadCachedMessages,
   persistMessages,
@@ -70,7 +71,12 @@ function rowToMessage(row: Record<string, unknown>): MessageWithCipher {
 }
 
 export function useConversationMessages({ conversationId, userId, deviceId }: Args): State & {
-  send: (text: string, images?: File[], replyToId?: string | null) => Promise<void>;
+  send: (
+    text: string,
+    images?: File[],
+    replyToId?: string | null,
+    opts?: { viewOnce?: boolean },
+  ) => Promise<void>;
   refresh: () => Promise<void>;
   pending: OutboxItem[];
   retryPending: (id: string) => void;
@@ -559,7 +565,12 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
   );
 
   const send = useCallback(
-    async (text: string, images: File[] = [], replyToId: string | null = null) => {
+    async (
+      text: string,
+      images: File[] = [],
+      replyToId: string | null = null,
+      opts: { viewOnce?: boolean } = {},
+    ) => {
       const trimmed = text.trim();
       if ((!trimmed && images.length === 0) || !conversationId || !userId || !deviceId) return;
       const priv = privateKeyRef.current;
@@ -622,6 +633,12 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           throw new Error('attachment exceeds max size (10 MB)');
         }
         const dims = await readImageDimensions(file);
+        // Phase 6B: generate a small WebP preview thumb so the receiver's
+        // bubble loads fast (typical 320×240 WebP is 10–30KB vs the full
+        // image's 1–10MB). `generateWebPThumb` short-circuits to null on
+        // non-images, animated formats, and small files — and on failure;
+        // the upload helper then just skips the second upload.
+        const thumbBlob = await generateWebPThumb(file);
         const res = await encryptAndUploadAttachment({
           client: supabase,
           conversationId,
@@ -630,7 +647,16 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           sizeBytes: file.size,
           ...(dims.width !== undefined ? { width: dims.width } : {}),
           ...(dims.height !== undefined ? { height: dims.height } : {}),
+          ...(thumbBlob ? { thumbBlob } : {}),
         });
+        // Stamp the view-once flag on each handle the caller requested it
+        // for. The flag rides inside the encrypted payload (so peers can
+        // render the locked card without leaking who-sent-what to the
+        // server) AND lands on the public message_attachments row via
+        // insertAttachmentRow below (where the mark-viewed RPC enforces it).
+        if (opts.viewOnce) {
+          res.handle.viewOnce = true;
+        }
         handles.push(res.handle);
         blobNonceHexByHandleId.set(res.handle.id, bytesToPgHex(res.nonce));
       }

apps/desktop/src/lib/useMentionNotifications.ts

@@ -0,0 +1,45 @@
+import { useEffect } from 'react';
+
+import { notify } from './osNotify';
+import { supabase } from './supabase';
+
+interface MentionRow {
+  message_id: string;
+  mentioned_user_id: string;
+  conversation_id: string;
+}
+
+// Subscribes to my own message_mentions inserts and fires an OS notification
+// for each one. Bypasses per-conv mute (mentions override mute by design).
+//
+// We don't decrypt the body here — the notification just says "Du wurdest
+// erwähnt". The conv list highlight + the in-app navigation reveal context.
+export function useMentionNotifications(userId: string | undefined): void {
+  useEffect(() => {
+    if (!userId) return;
+    const channel = supabase
+      .channel('mentions:' + userId)
+      .on(
+        'postgres_changes',
+        {
+          event: 'INSERT',
+          schema: 'public',
+          table: 'message_mentions',
+          filter: 'mentioned_user_id=eq.' + userId,
+        },
+        (payload) => {
+          const row = payload.new as MentionRow | null;
+          if (!row) return;
+          void notify({
+            title: 'Du wurdest erwähnt',
+            body: 'Tippe um die Nachricht zu lesen.',
+            force: true,
+          });
+        },
+      )
+      .subscribe();
+    return () => {
+      void supabase.removeChannel(channel);
+    };
+  }, [userId]);
+}

apps/desktop/src/lib/usePinnedMessages.ts

@@ -0,0 +1,99 @@
+import { listPinnedMessages, type PinnedMessage } from '@chat-app/shared/chat';
+import { useCallback, useEffect, useState } from 'react';
+
+import { supabase } from './supabase';
+
+export interface UsePinnedMessagesResult {
+  pins: PinnedMessage[];
+  // Optimistic insert. Caller flips the UI immediately; server insert +
+  // realtime echo will reconcile (dedup'd by messageId). Returns the
+  // previous snapshot so the caller can roll back on error.
+  applyOptimisticPin: (messageId: string, pinnedBy: string) => PinnedMessage[];
+  applyOptimisticUnpin: (messageId: string) => PinnedMessage[];
+  // Hard restore for rollback after a failed server call.
+  restorePins: (snapshot: PinnedMessage[]) => void;
+}
+
+// Live list of pinned messages for one conversation. Subscribes to the
+// `pinned_messages` realtime channel for the conv so the header pill +
+// side-panel update without a refetch. The `applyOptimistic*` helpers let
+// callers flip local state synchronously on user action so the pin button
+// doesn't appear unresponsive while the ~100-200ms server roundtrip + the
+// realtime refetch round complete.
+export function usePinnedMessages(conversationId: string | undefined): UsePinnedMessagesResult {
+  const [pins, setPins] = useState<PinnedMessage[]>([]);
+
+  useEffect(() => {
+    if (!conversationId) {
+      setPins([]);
+      return;
+    }
+    let cancelled = false;
+
+    void listPinnedMessages(supabase, conversationId).then((rows) => {
+      if (!cancelled) setPins(rows);
+    });
+
+    const channel = supabase
+      .channel('pinned_messages:' + conversationId)
+      .on(
+        'postgres_changes',
+        {
+          event: '*',
+          schema: 'public',
+          table: 'pinned_messages',
+          filter: 'conversation_id=eq.' + conversationId,
+        },
+        () => {
+          void listPinnedMessages(supabase, conversationId).then((rows) => {
+            if (!cancelled) setPins(rows);
+          });
+        },
+      )
+      .subscribe();
+
+    return () => {
+      cancelled = true;
+      void supabase.removeChannel(channel);
+    };
+  }, [conversationId]);
+
+  const applyOptimisticPin = useCallback<UsePinnedMessagesResult['applyOptimisticPin']>(
+    (messageId, pinnedBy) => {
+      if (!conversationId) return pins;
+      let snapshot: PinnedMessage[] = pins;
+      setPins((prev) => {
+        snapshot = prev;
+        if (prev.some((p) => p.messageId === messageId)) return prev;
+        const optimistic: PinnedMessage = {
+          conversationId,
+          messageId,
+          pinnedBy,
+          pinnedAt: new Date().toISOString(),
+        };
+        // Newest first matches the listPinnedMessages order.
+        return [optimistic, ...prev];
+      });
+      return snapshot;
+    },
+    [conversationId, pins],
+  );
+
+  const applyOptimisticUnpin = useCallback<UsePinnedMessagesResult['applyOptimisticUnpin']>(
+    (messageId) => {
+      let snapshot: PinnedMessage[] = pins;
+      setPins((prev) => {
+        snapshot = prev;
+        return prev.filter((p) => p.messageId !== messageId);
+      });
+      return snapshot;
+    },
+    [pins],
+  );
+
+  const restorePins = useCallback<UsePinnedMessagesResult['restorePins']>((snapshot) => {
+    setPins(snapshot);
+  }, []);
+
+  return { pins, applyOptimisticPin, applyOptimisticUnpin, restorePins };
+}

apps/desktop/src/lib/userIdentity.ts

@@ -3,11 +3,12 @@ import {
   resetUserKey, tryUnlockUserKey, uploadUserKeyBlob,
 } from '@chat-app/shared/auth';
 import {
-  generateRecoveryCode, generateUserKeyPair, normalizeRecoveryCode,
-  openUserKey, sealUserKey,
+  generateRecoveryCode, generateUserKeyPair, getCryptoBackend, normalizeRecoveryCode,
+  sealUserKey,
 } from '@chat-app/shared/crypto';
 import { migrateOwnLegacyBundles } from '@chat-app/shared/chat';
 
+import { openUserKeyMaybeWorker } from './cryptoWorker';
 import { devLocalSecretStore } from './secretStore';
 import { supabase } from './supabase';
 
@@ -50,7 +51,7 @@ export async function setupNewUserIdentity(p: SetupParams): Promise<SetupResult>
 export async function ensureLegacyMigrated(userId: string): Promise<void> {
   const priv = await devLocalSecretStore.getSecret(cacheKey(userId));
   if (!priv) return;
-  const pub = await derivePublicKey(priv);
+  const pub = derivePublicKey(priv);
   await runLegacyMigration(userId, priv, pub);
 }
 
@@ -71,7 +72,7 @@ export async function loadOrUnlockUserKey(p: UnlockParams): Promise<UnlockOutcom
   if (!sealed || !salt) throw new Error('no recovery blob configured');
   let priv: Uint8Array;
   try {
-    priv = await openUserKey({ sealed, pin: secret, salt, kdfParams: remote.kdfParams });
+    priv = await openUserKeyMaybeWorker({ sealed, pin: secret, salt, kdfParams: remote.kdfParams });
   } catch (err) {
     await recordPinAttempt(supabase, p.userId, false, p.isRecoveryCode === true).catch(() => {});
     throw err;
@@ -105,7 +106,7 @@ export async function changePin(params: {
   const fresh = await sealUserKey({ privateKey: cached, pin: params.newPin });
   await uploadUserKeyBlob(supabase, {
     userId: params.userId,
-    publicKey: await derivePublicKey(cached),
+    publicKey: derivePublicKey(cached),
     sealedPrivateKey: fresh.sealedPrivateKey,
     salt: fresh.salt,
     kdfParams: fresh.kdfParams,
@@ -122,7 +123,7 @@ export async function regenerateRecoveryCode(params: { userId: string }): Promis
   const sealed = await sealUserKey({ privateKey: cached, pin: normalizeRecoveryCode(recoveryCode) });
   await uploadUserKeyBlob(supabase, {
     userId: params.userId,
-    publicKey: await derivePublicKey(cached),
+    publicKey: derivePublicKey(cached),
     sealedPrivateKey: blob.sealedPrivateKey,
     salt: blob.salt,
     kdfParams: blob.kdfParams,
@@ -247,12 +248,10 @@ async function runLegacyMigration(
 export async function retryLegacyMigration(userId: string): Promise<LegacyMigrationReport> {
   const priv = await devLocalSecretStore.getSecret(cacheKey(userId));
   if (!priv) throw new Error('user key not cached locally — re-login required');
-  const pub = await derivePublicKey(priv);
+  const pub = derivePublicKey(priv);
   return runLegacyMigration(userId, priv, pub);
 }
 
-async function derivePublicKey(privateKey: Uint8Array): Promise<Uint8Array> {
-  const sodium = (await import('libsodium-wrappers-sumo')).default;
-  await sodium.ready;
-  return sodium.crypto_scalarmult_base(privateKey);
+function derivePublicKey(privateKey: Uint8Array): Uint8Array {
+  return getCryptoBackend().scalarMultBase(privateKey);
 }

apps/desktop/src/lib/voiceHotkeys.ts

@@ -20,6 +20,13 @@ export interface VoiceHotkeyBinding {
   shift: boolean;
   alt: boolean;
   enabled: boolean;
+  /**
+   * When true, the hotkey is registered as an OS-level shortcut and fires
+   * even when the app isn't focused. When false (default) the binding only
+   * fires from the window's keydown listener — so e.g. setting "M" as mute
+   * doesn't break typing "m" everywhere else on the system.
+   */
+  global: boolean;
 }
 
 export interface VoiceHotkeys {
@@ -36,46 +43,11 @@ export interface VoiceHotkeys {
 export type VoiceHotkeyKind = keyof VoiceHotkeys;
 
 const DEFAULTS: VoiceHotkeys = {
-  mute: {
-    key: 'KeyM',
-    keyLabel: 'Ctrl+Shift+M',
-    ctrl: true,
-    shift: true,
-    alt: false,
-    enabled: false,
-  },
-  deafen: {
-    key: 'KeyD',
-    keyLabel: 'Ctrl+Shift+D',
-    ctrl: true,
-    shift: true,
-    alt: false,
-    enabled: false,
-  },
-  hangup: {
-    key: 'KeyH',
-    keyLabel: 'Ctrl+Shift+H',
-    ctrl: true,
-    shift: true,
-    alt: false,
-    enabled: false,
-  },
-  screenShare: {
-    key: 'KeyE',
-    keyLabel: 'Ctrl+Shift+E',
-    ctrl: true,
-    shift: true,
-    alt: false,
-    enabled: false,
-  },
-  video: {
-    key: 'KeyV',
-    keyLabel: 'Ctrl+Shift+V',
-    ctrl: true,
-    shift: true,
-    alt: false,
-    enabled: false,
-  },
+  mute:        { key: 'KeyM', keyLabel: 'Ctrl+Shift+M', ctrl: true, shift: true, alt: false, enabled: false, global: false },
+  deafen:      { key: 'KeyD', keyLabel: 'Ctrl+Shift+D', ctrl: true, shift: true, alt: false, enabled: false, global: false },
+  hangup:      { key: 'KeyH', keyLabel: 'Ctrl+Shift+H', ctrl: true, shift: true, alt: false, enabled: false, global: false },
+  screenShare: { key: 'KeyE', keyLabel: 'Ctrl+Shift+E', ctrl: true, shift: true, alt: false, enabled: false, global: false },
+  video:       { key: 'KeyV', keyLabel: 'Ctrl+Shift+V', ctrl: true, shift: true, alt: false, enabled: false, global: false },
 };
 
 type Listener = (s: VoiceHotkeys) => void;
@@ -93,6 +65,7 @@ function validateBinding(raw: unknown, fallback: VoiceHotkeyBinding): VoiceHotke
     shift: typeof b.shift === 'boolean' ? b.shift : fallback.shift,
     alt: typeof b.alt === 'boolean' ? b.alt : fallback.alt,
     enabled: typeof b.enabled === 'boolean' ? b.enabled : fallback.enabled,
+    global: typeof b.global === 'boolean' ? b.global : fallback.global,
   };
 }
 

apps/desktop/src/pages/ChatsPage.tsx

@@ -2,10 +2,11 @@ import { acceptDm, type ConversationSummary, isConversationMuted } from '@chat-a
 import { extractErrorCode } from '@chat-app/shared/i18n';
 import { useEffect, useMemo, useRef, useState } from 'react';
 import { useTranslation } from 'react-i18next';
-import { NavLink, Outlet, useParams } from 'react-router-dom';
+import { NavLink, Outlet, useNavigate, useParams } from 'react-router-dom';
 
 import { ConversationRowMenu } from '../components/ConversationRowMenu';
 import { CreateGroupDialog } from '../components/CreateGroupDialog';
+import { EmptyState } from '../components/EmptyState';
 import {
   AddUserIcon,
   ArchiveIcon,
@@ -119,6 +120,7 @@ function ConversationList({
   archivedCount,
 }: ConversationListProps) {
   const { t } = useTranslation(['app']);
+  const navigate = useNavigate();
 
   return (
     <aside
@@ -222,28 +224,36 @@ function ConversationList({
         </div>
       ) : error ? (
         <p className="px-4 py-2 text-xs text-rose-500 dark:text-rose-300">{error}</p>
+      ) : query.trim().length > 0 && items.length === 0 ? (
+        <EmptyState
+          icon={<SearchIcon className="h-8 w-8" />}
+          title={t('app:chats.search_empty_title', { defaultValue: 'Keine Treffer' })}
+          description={t('app:chats.search_empty_desc', {
+            defaultValue: 'Keine Chats passen zu "' + query.trim() + '".',
+          })}
+        />
       ) : items.length === 0 ? (
-        <div className="flex flex-1 flex-col items-center justify-center gap-3 px-6 text-center">
-          <div className="flex h-12 w-12 items-center justify-center rounded-2xl border border-line bg-surface-3 text-accent">
-            {showArchived ? (
-              <ArchiveIcon className="h-5 w-5" />
-            ) : (
-              <ChatBubbleIcon className="h-5 w-5" />
-            )}
-          </div>
-          <p className="text-sm text-fg-muted">
-            {showArchived
-              ? t('app:chats.archived_empty_title', { defaultValue: 'Nichts archiviert' })
-              : t('app:chats.empty_title')}
-          </p>
-          <p className="text-xs text-fg-muted/80">
-            {showArchived
-              ? t('app:chats.archived_empty_subtitle', {
-                  defaultValue: 'Archivierte Unterhaltungen erscheinen hier.',
-                })
-              : t('app:chats.empty_subtitle')}
-          </p>
-        </div>
+        showArchived ? (
+          <EmptyState
+            icon={<ArchiveIcon className="h-8 w-8" />}
+            title={t('app:chats.archived_empty_title', { defaultValue: 'Nichts archiviert' })}
+            description={t('app:chats.archived_empty_subtitle', {
+              defaultValue: 'Archivierte Unterhaltungen erscheinen hier.',
+            })}
+          />
+        ) : (
+          <EmptyState
+            icon={<ChatBubbleIcon className="h-8 w-8" />}
+            title={t('app:chats.empty_title', { defaultValue: 'Noch keine Chats' })}
+            description={t('app:chats.empty_desc', {
+              defaultValue: 'Lade einen Freund ein und schreibe die erste Nachricht.',
+            })}
+            action={{
+              label: t('app:chats.empty_cta', { defaultValue: 'Freunde verwalten' }),
+              onClick: () => navigate('/friends'),
+            }}
+          />
+        )
       ) : (
         <VirtualConversationList
           items={items}
@@ -415,6 +425,7 @@ function ConversationRow({
         conversationId={item.id}
         archived={item.archived}
         mutedUntil={item.mutedUntil}
+        mentionsOnly={item.mentionsOnly}
       />
     </NavLink>
   );

apps/desktop/src/pages/FriendsPage.tsx

@@ -8,12 +8,15 @@ import {
   sendFriendRequest,
 } from '@chat-app/shared/friends';
 import { extractErrorCode } from '@chat-app/shared/i18n';
-import { useCallback, useEffect, useMemo, useState } from 'react';
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useNavigate } from 'react-router-dom';
 
 import { Avatar } from '../components/Avatar';
+import { EmptyState } from '../components/EmptyState';
+import { NicknameDialog } from '../components/NicknameDialog';
 import {
+  AddUserIcon,
   AlertIcon,
   ChatBubbleIcon,
   CheckCircleIcon,
@@ -39,6 +42,12 @@ export function FriendsPage() {
   const [searchError, setSearchError] = useState<string | null>(null);
   const [pendingId, setPendingId] = useState<string | null>(null);
   const [actionError, setActionError] = useState<string | null>(null);
+  const [nicknameDialog, setNicknameDialog] = useState<{ userId: string; displayName: string } | null>(null);
+  const searchInputRef = useRef<HTMLInputElement | null>(null);
+
+  const focusSearch = useCallback(() => {
+    searchInputRef.current?.focus();
+  }, []);
 
   useEffect(() => {
     const id = window.setTimeout(() => setDebounced(query.trim()), 250);
@@ -119,6 +128,7 @@ export function FriendsPage() {
         <div className="relative">
           <SearchIcon className="pointer-events-none absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-fg-muted" />
           <input
+            ref={searchInputRef}
             type="search"
             value={query}
             onChange={(e) => setQuery(e.target.value)}
@@ -160,24 +170,44 @@ export function FriendsPage() {
       {loading ? (
         <LoadingRow />
       ) : tab === 'friends' ? (
-        <FriendList
-          items={accepted}
-          emptyKey="app:friends.empty_friends"
-          renderActions={(f) => (
-            <FriendActions
-              busy={pendingId === f.peer.userId || pendingId === 'msg-' + f.peer.userId}
-              onMessage={() =>
-                performAction('msg-' + f.peer.userId, async () => {
-                  const id = await createDm(supabase, f.peer.userId);
-                  navigate('/chats/' + id);
-                })
-              }
-              onUnfriend={() =>
-                performAction(f.peer.userId, () => removeFriendship(supabase, f.peer.userId))
-              }
-            />
-          )}
-        />
+        accepted.length === 0 ? (
+          <EmptyState
+            icon={<AddUserIcon className="h-8 w-8" />}
+            title={t('app:friends.empty_title', { defaultValue: 'Noch keine Freunde' })}
+            description={t('app:friends.empty_desc', {
+              defaultValue: 'Suche einen Friend per Username oder schicke eine Einladung.',
+            })}
+            action={{
+              label: t('app:friends.empty_cta', { defaultValue: 'Friend hinzufügen' }),
+              onClick: focusSearch,
+            }}
+          />
+        ) : (
+          <FriendList
+            items={accepted}
+            emptyKey="app:friends.empty_friends"
+            onRowContextMenu={(f) =>
+              setNicknameDialog({
+                userId: f.peer.userId,
+                displayName: f.peer.displayName ?? f.peer.username ?? 'Freund',
+              })
+            }
+            renderActions={(f) => (
+              <FriendActions
+                busy={pendingId === f.peer.userId || pendingId === 'msg-' + f.peer.userId}
+                onMessage={() =>
+                  performAction('msg-' + f.peer.userId, async () => {
+                    const id = await createDm(supabase, f.peer.userId);
+                    navigate('/chats/' + id);
+                  })
+                }
+                onUnfriend={() =>
+                  performAction(f.peer.userId, () => removeFriendship(supabase, f.peer.userId))
+                }
+              />
+            )}
+          />
+        )
       ) : tab === 'pending' ? (
         <FriendList
           items={outgoing}
@@ -211,6 +241,12 @@ export function FriendsPage() {
         />
       )}
       </div>
+      <NicknameDialog
+        open={nicknameDialog !== null}
+        userId={nicknameDialog?.userId ?? ''}
+        displayName={nicknameDialog?.displayName ?? ''}
+        onClose={() => setNicknameDialog(null)}
+      />
     </div>
   );
 }
@@ -253,10 +289,12 @@ function FriendList({
   items,
   emptyKey,
   renderActions,
+  onRowContextMenu,
 }: {
   items: Friendship[];
   emptyKey: string;
   renderActions: (f: Friendship) => React.ReactNode;
+  onRowContextMenu?: (f: Friendship) => void;
 }) {
   const { t } = useTranslation(['app']);
   if (items.length === 0) {
@@ -274,16 +312,39 @@ function FriendList({
     <ul className="space-y-1.5">
       {items.map((f) => (
         <li key={f.peer.userId}>
-          <FriendRow profile={f.peer}>{renderActions(f)}</FriendRow>
+          <FriendRow
+            profile={f.peer}
+            {...(onRowContextMenu
+              ? {
+                  onContextMenu: (e: React.MouseEvent<HTMLDivElement>) => {
+                    e.preventDefault();
+                    onRowContextMenu(f);
+                  },
+                }
+              : {})}
+          >
+            {renderActions(f)}
+          </FriendRow>
         </li>
       ))}
     </ul>
   );
 }
 
-function FriendRow({ profile, children }: { profile: ProfileBrief; children: React.ReactNode }) {
+function FriendRow({
+  profile,
+  children,
+  onContextMenu,
+}: {
+  profile: ProfileBrief;
+  children: React.ReactNode;
+  onContextMenu?: (e: React.MouseEvent<HTMLDivElement>) => void;
+}) {
   return (
-    <div className="flex items-center gap-3 rounded-xl border border-line bg-surface-2 px-4 py-3">
+    <div
+      onContextMenu={onContextMenu}
+      className="flex items-center gap-3 rounded-xl border border-line bg-surface-2 px-4 py-3"
+    >
       <Avatar
         url={profile.avatarUrl}
         displayName={profile.displayName ?? profile.username}

apps/desktop/src/pages/SettingsPage.tsx

@@ -23,6 +23,7 @@ import {
 import { MicTestSection } from '../components/MicTestSection';
 import { NotificationSoundSettings } from '../components/NotificationSoundSettings';
 import { RingtoneSettings } from '../components/RingtoneSettings';
+import { DeviceListTab } from '../components/settings/DeviceListTab';
 import { SecurityCenter } from '../components/SecurityCenter';
 import { SoundboardSettings } from '../components/SoundboardSettings';
 import { useAuth } from '../context/AuthContext';
@@ -117,7 +118,7 @@ export function SettingsPage() {
   // routing conflict with HashRouter.
   type TabId =
     | 'profile' | 'appearance' | 'privacy' | 'notifications'
-    | 'voice' | 'screen-share' | 'soundboard' | 'security' | 'account';
+    | 'voice' | 'screen-share' | 'soundboard' | 'security' | 'devices' | 'account';
 
   const tabs: Array<{ id: TabId; label: string; Icon: typeof UsersIcon }> = [
     { id: 'profile',       label: t('app:settings.nav_profile',       { defaultValue: 'Profil' }),               Icon: UsersIcon },
@@ -128,6 +129,7 @@ export function SettingsPage() {
     { id: 'screen-share',  label: t('app:settings.nav_screen_share',  { defaultValue: 'Bildschirmfreigabe' }), Icon: MonitorShareIcon },
     { id: 'soundboard',    label: t('app:settings.nav_soundboard',    { defaultValue: 'Soundboard' }),          Icon: MusicIcon },
     { id: 'security',      label: t('app:settings.nav_security',      { defaultValue: 'Sicherheit' }),          Icon: LockIcon },
+    { id: 'devices',       label: t('app:settings.nav_devices',       { defaultValue: 'Geräte' }),             Icon: MonitorShareIcon },
     { id: 'account',       label: t('app:settings.nav_account',       { defaultValue: 'Konto' }),               Icon: SignOutIcon },
   ];
 
@@ -352,6 +354,17 @@ export function SettingsPage() {
               </Section>
             )}
 
+            {activeTab === 'devices' && (
+              <Section
+                title={t('app:settings.section_devices', { defaultValue: 'Geräte' })}
+                description={t('app:settings.section_devices_hint', {
+                  defaultValue: 'Übersicht aller Geräte, die mit deinem Konto angemeldet sind.',
+                })}
+              >
+                <DeviceListTab />
+              </Section>
+            )}
+
             {activeTab === 'account' && (
               <Section
                 title={t('app:settings.section_account_mgmt', { defaultValue: 'Konto verwalten' })}
@@ -575,22 +588,44 @@ function VoiceHotkeyControls({ kind }: { kind: VoiceHotkeyKind }) {
       <SettingRow
         label={t('app:settings.hotkey_binding', { defaultValue: 'Hotkey' })}
       >
-        <button
-          type="button"
-          onClick={() => setCapturing((v) => !v)}
-          className={
-            'inline-flex min-w-[10rem] cursor-pointer items-center justify-center rounded-lg border px-3 py-1.5 text-xs font-mono font-semibold transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
-            (capturing
-              ? 'border-accent bg-accent/20 text-fg animate-pulse'
-              : 'border-line bg-surface-3 text-fg hover:brightness-95')
-          }
-        >
-          {capturing
-            ? t('app:settings.hotkey_press_combo', {
-                defaultValue: 'Kombination drücken…',
-              })
-            : binding.keyLabel}
-        </button>
+        <div className="flex items-center gap-2">
+          <button
+            type="button"
+            onClick={() => setCapturing((v) => !v)}
+            className={
+              'inline-flex min-w-[10rem] cursor-pointer items-center justify-center rounded-lg border px-3 py-1.5 text-xs font-mono font-semibold transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
+              (capturing
+                ? 'border-accent bg-accent/20 text-fg animate-pulse'
+                : 'border-line bg-surface-3 text-fg hover:brightness-95')
+            }
+          >
+            {capturing
+              ? t('app:settings.hotkey_press_combo', {
+                  defaultValue: 'Kombination drücken…',
+                })
+              : binding.keyLabel}
+          </button>
+          <button
+            type="button"
+            onClick={() => updateVoiceHotkey(kind, { global: !binding.global })}
+            disabled={!binding.enabled}
+            aria-pressed={binding.global}
+            title={
+              binding.global
+                ? 'Global: feuert auch wenn Netralax nicht fokussiert ist (PTT-Stil)'
+                : 'Nur im Fenster: feuert nur wenn Netralax fokussiert ist (empfohlen)'
+            }
+            className={
+              'ml-2 inline-flex h-7 cursor-pointer items-center gap-1 rounded-md border px-2 text-[11px] font-semibold transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 disabled:cursor-not-allowed disabled:opacity-50 ' +
+              (binding.global
+                ? 'border-accent/40 bg-accent/15 text-accent'
+                : 'border-line bg-surface-3 text-fg-muted hover:text-fg')
+            }
+          >
+            <span aria-hidden>🌐</span>
+            <span>{binding.global ? 'Global' : 'Im Fenster'}</span>
+          </button>
+        </div>
       </SettingRow>
     </>
   );

apps/desktop/src/styles/globals.css

@@ -85,9 +85,10 @@
     *,
     *::before,
     *::after {
-      animation-duration: 0.01ms !important;
+      animation-duration: 0.001ms !important;
       animation-iteration-count: 1 !important;
-      transition-duration: 0.01ms !important;
+      transition-duration: 0.001ms !important;
+      scroll-behavior: auto !important;
     }
   }
 }

apps/desktop/src/workers/crypto.worker.ts

@@ -0,0 +1,78 @@
+// Web Worker — runs Argon2id pwhash + sealed user-key open off the main
+// thread. PIN-unlock used to freeze the UI for ~1-2 s on mid-hardware while
+// the moderate-preset KDF ran; pushing it here keeps the unlock screen
+// responsive.
+//
+// The worker bundles its own libsodium-wrappers-sumo instance and registers
+// it as the shared CryptoBackend inside this worker realm — there is no
+// shared state with the main thread, so we initialise once per worker and
+// re-use it across messages (the client wrapper currently spawns one-shot,
+// but the worker is safe to keep alive too).
+//
+// Message protocol (one-shot RPC):
+//   request:  { op: 'openUserKey', input: OpenUserKeyInput }
+//   response: { ok: true,  result: { privateKey: Uint8Array } }
+//           | { ok: false, error: string }
+//
+// The private key bytes are transferred (zero-copy) back to the caller via
+// the structured-clone Transferable list; the worker's view of the buffer is
+// detached on transfer which also clears the only worker-side reference.
+
+/// <reference lib="webworker" />
+
+import { setCryptoBackend, openUserKey } from '@chat-app/shared/crypto';
+import type { KdfParams } from '@chat-app/shared/crypto';
+import sodium from 'libsodium-wrappers-sumo';
+
+import { createLibsodiumBackend } from '../lib/cryptoBackend';
+
+export interface OpenUserKeyInput {
+  sealed: Uint8Array;
+  pin: string;
+  salt: Uint8Array;
+  kdfParams: KdfParams;
+}
+
+export interface OpenUserKeyResult {
+  privateKey: Uint8Array;
+}
+
+type WorkerRequest = { op: 'openUserKey'; input: OpenUserKeyInput };
+type WorkerResponse =
+  | { ok: true; result: OpenUserKeyResult }
+  | { ok: false; error: string };
+
+let backendReady: Promise<void> | null = null;
+
+async function ensureBackend(): Promise<void> {
+  if (!backendReady) {
+    backendReady = (async () => {
+      await sodium.ready;
+      setCryptoBackend(await createLibsodiumBackend());
+    })();
+  }
+  return backendReady;
+}
+
+self.addEventListener('message', (ev: MessageEvent<WorkerRequest>) => {
+  const msg = ev.data;
+  void (async () => {
+    try {
+      if (!msg || msg.op !== 'openUserKey') {
+        throw new Error('unknown op: ' + String((msg as { op?: unknown })?.op));
+      }
+      await ensureBackend();
+      const privateKey = await openUserKey(msg.input);
+      const response: WorkerResponse = { ok: true, result: { privateKey } };
+      const transfers: Transferable[] = [];
+      if (privateKey?.buffer instanceof ArrayBuffer) {
+        transfers.push(privateKey.buffer);
+      }
+      (self as unknown as Worker).postMessage(response, transfers);
+    } catch (err) {
+      const message = err instanceof Error ? err.message : String(err);
+      const response: WorkerResponse = { ok: false, error: message };
+      (self as unknown as Worker).postMessage(response);
+    }
+  })();
+});

apps/mobile/README.md

@@ -73,6 +73,23 @@ Copy `.env.example` to `.env.local` and fill in the same Supabase host +
 anon key the desktop uses. Expo bundles only `EXPO_PUBLIC_*`-prefixed
 vars into the JS, which is what the three required values use.
 
+## EAS Builds and Environment Variables
+
+Production and preview builds load `EXPO_PUBLIC_*` from EAS Secrets —
+`.env.local` is only honoured by `expo start` locally. Without the
+secrets configured, an APK installs but `env.ts` throws on first read
+and `<BootError>` renders.
+
+Required secrets (create once per project):
+
+```bash
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_URL --value '<project-supabase-url>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_ANON_KEY --value '<sb_publishable_key>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_AUTH_REDIRECT_URL --value 'netralax://auth/callback'
+```
+
+Check with `npx eas-cli secret:list`.
+
 ## Roadmap
 
 See `docs/superpowers/specs/2026-05-13-mobile-deployment-roadmap.md`.

apps/mobile/app/(app)/_layout.tsx

@@ -1,19 +1,42 @@
 import { Redirect, Stack } from 'expo-router';
+import { ActivityIndicator, StyleSheet, View } from 'react-native';
 
 import { useAuth } from '../../lib/authContext';
+import { colors } from '../../theme/colors';
 
 export default function AppLayout() {
-  const { session, loading } = useAuth();
-  if (loading) return null;
+  const { ready, session, userKeyState } = useAuth();
+
+  if (!ready) {
+    return (
+      <View style={styles.center}>
+        <ActivityIndicator color={colors.accent} />
+      </View>
+    );
+  }
   if (!session) return <Redirect href="/" />;
+  if (userKeyState.status === 'loading') {
+    return (
+      <View style={styles.center}>
+        <ActivityIndicator color={colors.accent} />
+      </View>
+    );
+  }
+  if (userKeyState.status === 'needs-setup') return <Redirect href="/(app)/setup" />;
+  if (userKeyState.status === 'needs-unlock') return <Redirect href="/(app)/unlock" />;
+
   return (
-    <Stack screenOptions={{ headerShown: true }}>
+    <Stack screenOptions={{ headerStyle: { backgroundColor: colors.bg } }}>
       <Stack.Screen name="chats" />
       <Stack.Screen name="conversations/[id]" />
-      <Stack.Screen
-        name="call"
-        options={{ headerShown: false, presentation: 'fullScreenModal' }}
-      />
+      <Stack.Screen name="call" options={{ presentation: 'fullScreenModal' }} />
+      <Stack.Screen name="settings" options={{ presentation: 'card' }} />
+      <Stack.Screen name="setup" options={{ headerShown: false }} />
+      <Stack.Screen name="unlock" options={{ headerShown: false }} />
     </Stack>
   );
 }
+
+const styles = StyleSheet.create({
+  center: { flex: 1, alignItems: 'center', justifyContent: 'center', backgroundColor: colors.bg },
+});

apps/mobile/app/(app)/chats.tsx

@@ -4,7 +4,6 @@ import { Stack, useRouter } from 'expo-router';
 import { useCallback, useEffect, useState } from 'react';
 import {
   ActivityIndicator,
-  Alert,
   FlatList,
   Pressable,
   RefreshControl,
@@ -14,7 +13,6 @@ import {
 } from 'react-native';
 
 import { ConversationRow } from '../../components/ConversationRow';
-import { useAuth } from '../../lib/authContext';
 import { supabase } from '../../lib/supabase';
 import { colors } from '../../theme/colors';
 
@@ -23,7 +21,6 @@ import { colors } from '../../theme/colors';
 // is a Phase 1.5 follow-up. Tap → conversation detail.
 export default function Chats() {
   const router = useRouter();
-  const { signOut } = useAuth();
   const [list, setList] = useState<ConversationSummary[] | null>(null);
   const [refreshing, setRefreshing] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -48,19 +45,6 @@ export default function Chats() {
     setRefreshing(false);
   }, [load]);
 
-  const confirmLogout = () => {
-    Alert.alert('Abmelden', 'Diese Sitzung beenden?', [
-      { text: 'Abbrechen', style: 'cancel' },
-      {
-        text: 'Abmelden',
-        style: 'destructive',
-        onPress: () => {
-          void signOut();
-        },
-      },
-    ]);
-  };
-
   return (
     <View style={styles.container}>
       <Stack.Screen
@@ -69,8 +53,8 @@ export default function Chats() {
           headerStyle: { backgroundColor: colors.bg },
           headerTitleStyle: { color: colors.text },
           headerRight: () => (
-            <Pressable onPress={confirmLogout} hitSlop={10}>
-              <Text style={styles.logoutLink}>Abmelden</Text>
+            <Pressable onPress={() => router.push('/(app)/settings')} hitSlop={10}>
+              <Text style={styles.logoutLink}>Einstellungen</Text>
             </Pressable>
           ),
         }}

apps/mobile/app/(app)/conversations/[id].tsx

@@ -30,7 +30,7 @@ import { colors } from '../../../theme/colors';
 
 export default function ConversationDetail() {
   const { id } = useLocalSearchParams<{ id: string }>();
-  const { user, device, ownPrivateKey } = useAuth();
+  const { user, userId, ownPrivateKey } = useAuth();
   const { state: callState, startCall } = useCall();
   const router = useRouter();
 
@@ -54,7 +54,7 @@ export default function ConversationDetail() {
   const listRef = useRef<FlatList<DecryptedMessage>>(null);
 
   const load = useCallback(async () => {
-    if (!id || !device || !ownPrivateKey) return;
+    if (!id || !userId || !ownPrivateKey) return;
     setError(null);
     try {
       const all = await chat.listConversations(supabase);
@@ -63,7 +63,7 @@ export default function ConversationDetail() {
       const decrypted = await chat.decryptMessages({
         client: supabase,
         messages: ciphers,
-        ownDeviceId: device.id,
+        ownUserId: userId,
         ownPrivateKey,
       });
       setMessages(decrypted);
@@ -81,7 +81,7 @@ export default function ConversationDetail() {
     } catch (err: unknown) {
       setError(err instanceof Error ? err.message : 'Nachrichten konnten nicht geladen werden');
     }
-  }, [id, device, ownPrivateKey]);
+  }, [id, userId, ownPrivateKey]);
 
   useEffect(() => {
     void load();
@@ -103,7 +103,7 @@ export default function ConversationDetail() {
       : (conversation?.peer?.displayName ?? '…');
 
   async function handleSendText() {
-    if (!text.trim() || !user || !device || !ownPrivateKey || !id || sending) return;
+    if (!text.trim() || !user || !ownPrivateKey || !id || sending) return;
     setSending(true);
     setError(null);
     const replyToId = replyTo?.id;
@@ -113,7 +113,6 @@ export default function ConversationDetail() {
         conversationId: id,
         plaintext: text.trim(),
         senderUserId: user.id,
-        senderDeviceId: device.id,
         senderPrivateKey: ownPrivateKey,
         ...(replyToId ? { replyToId } : {}),
       });
@@ -128,7 +127,7 @@ export default function ConversationDetail() {
   }
 
   async function sendImage(pick: PickedImage) {
-    if (!user || !device || !ownPrivateKey || !id) return;
+    if (!user || !ownPrivateKey || !id) return;
     setSending(true);
     setError(null);
     try {
@@ -148,7 +147,6 @@ export default function ConversationDetail() {
         conversationId: id,
         plaintext: '',
         senderUserId: user.id,
-        senderDeviceId: device.id,
         senderPrivateKey: ownPrivateKey,
         attachmentHandles: [result.handle],
       });
@@ -300,7 +298,6 @@ export default function ConversationDetail() {
                 })}
                 reactions={reactions.get(item.id) ?? []}
                 myUserId={user?.id ?? null}
-                ownDeviceId={device?.id ?? null}
                 ownPrivateKey={ownPrivateKey}
                 onLongPress={() => setActiveMessage(item)}
                 onToggleReaction={(emoji) => {

apps/mobile/app/(app)/settings/_layout.tsx

@@ -0,0 +1,18 @@
+import { Stack } from 'expo-router';
+
+import { colors } from '../../../theme/colors';
+
+export default function SettingsLayout() {
+  return (
+    <Stack
+      screenOptions={{
+        headerStyle: { backgroundColor: colors.bg },
+        headerTitleStyle: { color: colors.text },
+        headerTintColor: colors.accent,
+      }}
+    >
+      <Stack.Screen name="index" options={{ title: 'Einstellungen' }} />
+      <Stack.Screen name="security" options={{ title: 'Sicherheit' }} />
+    </Stack>
+  );
+}

apps/mobile/app/(app)/settings/index.tsx

@@ -0,0 +1,44 @@
+import { useRouter } from 'expo-router';
+import { Alert, Pressable, StyleSheet, Text, View } from 'react-native';
+
+import { useAuth } from '../../../lib/authContext';
+import { colors } from '../../../theme/colors';
+
+export default function SettingsIndex() {
+  const router = useRouter();
+  const { signOut } = useAuth();
+
+  function confirmLogout() {
+    Alert.alert('Abmelden', 'Diese Sitzung beenden?', [
+      { text: 'Abbrechen', style: 'cancel' },
+      { text: 'Abmelden', style: 'destructive', onPress: () => void signOut() },
+    ]);
+  }
+
+  return (
+    <View style={styles.container}>
+      <Pressable style={styles.row} onPress={() => router.push('/(app)/settings/security')}>
+        <Text style={styles.rowTitle}>Sicherheit</Text>
+        <Text style={styles.rowHint}>PIN ändern, Recovery-Code, Identität zurücksetzen</Text>
+      </Pressable>
+      <Pressable style={[styles.row, styles.danger]} onPress={confirmLogout}>
+        <Text style={[styles.rowTitle, styles.dangerText]}>Abmelden</Text>
+      </Pressable>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: { flex: 1, backgroundColor: colors.bg, padding: 16, gap: 12 },
+  row: {
+    backgroundColor: colors.surface,
+    padding: 16,
+    borderRadius: 12,
+    borderColor: colors.border,
+    borderWidth: 1,
+  },
+  rowTitle: { color: colors.text, fontSize: 16, fontWeight: '600' },
+  rowHint: { color: colors.textMuted, fontSize: 13, marginTop: 4 },
+  danger: { borderColor: colors.danger },
+  dangerText: { color: colors.danger },
+});

apps/mobile/app/(app)/settings/security.tsx

@@ -0,0 +1,200 @@
+import { useState } from 'react';
+import {
+  ActivityIndicator,
+  Alert,
+  Pressable,
+  ScrollView,
+  StyleSheet,
+  Text,
+  View,
+} from 'react-native';
+
+import { PinInput } from '../../../components/PinInput';
+import { useAuth } from '../../../lib/authContext';
+import {
+  changePin,
+  regenerateRecoveryCode,
+  resetIdentity,
+  retryLegacyMigration,
+  type LegacyMigrationReport,
+} from '../../../lib/userIdentity';
+import { colors } from '../../../theme/colors';
+
+export default function SecuritySettings() {
+  const { userId, refreshUserKeyState } = useAuth();
+  const [oldPin, setOldPin] = useState('');
+  const [newPin, setNewPin] = useState('');
+  const [newRecovery, setNewRecovery] = useState<string | null>(null);
+  const [submitting, setSubmitting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [report, setReport] = useState<LegacyMigrationReport | null>(null);
+
+  async function handleChangePin() {
+    if (!userId) return;
+    if (oldPin.length !== 6 || newPin.length !== 6) {
+      setError('Beide PINs müssen 6 Ziffern haben.');
+      return;
+    }
+    setSubmitting(true);
+    setError(null);
+    try {
+      await changePin({ userId, oldPin, newPin });
+      setOldPin('');
+      setNewPin('');
+      Alert.alert('PIN geändert', 'Die neue PIN gilt sofort auf allen Geräten.');
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'PIN-Änderung fehlgeschlagen');
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  async function handleRegenerateRecovery() {
+    if (!userId) return;
+    setSubmitting(true);
+    setError(null);
+    try {
+      const code = await regenerateRecoveryCode({ userId });
+      setNewRecovery(code);
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Recovery-Code-Erzeugung fehlgeschlagen');
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  function handleReset() {
+    if (!userId) return;
+    Alert.alert(
+      'Identität zurücksetzen?',
+      'Alle bisherigen Chats werden für dich unlesbar. Diese Aktion kann nicht rückgängig gemacht werden.',
+      [
+        { text: 'Abbrechen', style: 'cancel' },
+        {
+          text: 'Zurücksetzen',
+          style: 'destructive',
+          onPress: async () => {
+            setSubmitting(true);
+            try {
+              await resetIdentity({ userId, pin: '000000' });
+              await refreshUserKeyState();
+            } catch (e) {
+              setError(e instanceof Error ? e.message : 'Reset fehlgeschlagen');
+            } finally {
+              setSubmitting(false);
+            }
+          },
+        },
+      ],
+    );
+  }
+
+  async function handleRetryMigration() {
+    if (!userId) return;
+    setSubmitting(true);
+    setError(null);
+    try {
+      const r = await retryLegacyMigration(userId);
+      setReport(r);
+    } catch (e) {
+      setError(e instanceof Error ? e.message : 'Migration fehlgeschlagen');
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  return (
+    <ScrollView contentContainerStyle={styles.container}>
+      <Text style={styles.section}>PIN ändern</Text>
+      <Text style={styles.label}>Alte PIN</Text>
+      <PinInput value={oldPin} onChange={setOldPin} ariaLabel="Alte PIN" />
+      <Text style={styles.label}>Neue PIN</Text>
+      <PinInput value={newPin} onChange={setNewPin} ariaLabel="Neue PIN" />
+      <Pressable style={styles.primary} onPress={handleChangePin} disabled={submitting}>
+        {submitting ? (
+          <ActivityIndicator color={colors.text} />
+        ) : (
+          <Text style={styles.primaryText}>PIN aktualisieren</Text>
+        )}
+      </Pressable>
+
+      <Text style={styles.section}>Recovery-Code</Text>
+      <Pressable style={styles.primary} onPress={handleRegenerateRecovery} disabled={submitting}>
+        <Text style={styles.primaryText}>Neuen Recovery-Code erzeugen</Text>
+      </Pressable>
+      {newRecovery && (
+        <View style={styles.codeBox}>
+          <Text style={styles.codeText} selectable>
+            {newRecovery}
+          </Text>
+        </View>
+      )}
+
+      <Text style={styles.section}>Migration</Text>
+      <Pressable style={styles.primary} onPress={handleRetryMigration} disabled={submitting}>
+        <Text style={styles.primaryText}>Migration erneut versuchen</Text>
+      </Pressable>
+      {report && (
+        <View style={styles.report}>
+          <Text style={styles.reportLine}>Geräte (Server): {report.serverDevices}</Text>
+          <Text style={styles.reportLine}>
+            Lokale Schlüssel im Vault:{' '}
+            {report.strongholdKeysFromServerDevices + report.strongholdKeysFromBundleScan}
+          </Text>
+          <Text style={styles.reportLine}>
+            Versucht: {report.attempted}, Erfolgreich: {report.migrated}
+          </Text>
+          <Text style={styles.reportLine}>
+            Übersprungen: kein lokaler Schlüssel = {report.noStrongholdKey}, Decrypt-Fehler ={' '}
+            {report.decryptFailed}, RPC-Fehler = {report.rpcFailed}
+          </Text>
+        </View>
+      )}
+
+      <Text style={styles.section}>Gefahrenbereich</Text>
+      <Pressable style={[styles.primary, styles.danger]} onPress={handleReset} disabled={submitting}>
+        <Text style={[styles.primaryText, styles.dangerText]}>Identität zurücksetzen</Text>
+      </Pressable>
+
+      {error && <Text style={styles.error}>{error}</Text>}
+    </ScrollView>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: { padding: 16, gap: 8, backgroundColor: colors.bg },
+  section: { color: colors.text, fontSize: 16, fontWeight: '700', marginTop: 16 },
+  label: { color: colors.textMuted, fontSize: 12, marginTop: 4 },
+  primary: {
+    backgroundColor: colors.accent,
+    paddingVertical: 14,
+    borderRadius: 12,
+    alignItems: 'center',
+    marginTop: 8,
+  },
+  primaryText: { color: colors.text, fontWeight: '700' },
+  danger: { backgroundColor: 'transparent', borderColor: colors.danger, borderWidth: 1 },
+  dangerText: { color: colors.danger },
+  codeBox: {
+    backgroundColor: colors.surface,
+    padding: 12,
+    borderRadius: 10,
+    marginTop: 4,
+  },
+  codeText: {
+    color: colors.text,
+    fontFamily: 'Courier',
+    fontSize: 16,
+    letterSpacing: 1.2,
+    textAlign: 'center',
+  },
+  report: {
+    backgroundColor: colors.surface,
+    padding: 12,
+    borderRadius: 10,
+    marginTop: 4,
+    gap: 4,
+  },
+  reportLine: { color: colors.text, fontSize: 13 },
+  error: { color: colors.danger, marginTop: 12 },
+});

apps/mobile/app/(app)/setup.tsx

@@ -0,0 +1,195 @@
+import { useRouter } from 'expo-router';
+import { useState } from 'react';
+import {
+  ActivityIndicator,
+  Alert,
+  Pressable,
+  ScrollView,
+  StyleSheet,
+  Text,
+  View,
+} from 'react-native';
+
+import { PinInput } from '../../components/PinInput';
+import { useAuth } from '../../lib/authContext';
+import { setupNewUserIdentity } from '../../lib/userIdentity';
+import { colors } from '../../theme/colors';
+
+type Step = 'pin' | 'confirm' | 'recovery' | 'done';
+
+export default function SetupScreen() {
+  const router = useRouter();
+  const { userId, refreshUserKeyState } = useAuth();
+  const [step, setStep] = useState<Step>('pin');
+  const [pin, setPin] = useState('');
+  const [confirm, setConfirm] = useState('');
+  const [recoveryCode, setRecoveryCode] = useState<string | null>(null);
+  const [withRecovery, setWithRecovery] = useState(true);
+  const [submitting, setSubmitting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  async function runSetup(saveRecovery: boolean) {
+    if (!userId) return;
+    setSubmitting(true);
+    setError(null);
+    try {
+      const out = await setupNewUserIdentity({ userId, pin, withRecovery: saveRecovery });
+      setRecoveryCode(out.recoveryCode);
+      if (out.recoveryCode) {
+        setStep('recovery');
+      } else {
+        setStep('done');
+        await refreshUserKeyState();
+        router.replace('/(app)/chats');
+      }
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Setup fehlgeschlagen');
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  if (step === 'pin') {
+    return (
+      <View style={styles.container}>
+        <Text style={styles.title}>PIN festlegen</Text>
+        <Text style={styles.subtitle}>
+          Mit dieser 6-stelligen PIN entsperrst du Netralax auf jedem Gerät.
+        </Text>
+        <PinInput value={pin} onChange={setPin} ariaLabel="Neue PIN" autoFocus />
+        {error && <Text style={styles.error}>{error}</Text>}
+        <Pressable
+          style={[styles.primary, pin.length !== 6 && styles.disabled]}
+          disabled={pin.length !== 6}
+          onPress={() => setStep('confirm')}
+        >
+          <Text style={styles.primaryText}>Weiter</Text>
+        </Pressable>
+      </View>
+    );
+  }
+
+  if (step === 'confirm') {
+    return (
+      <View style={styles.container}>
+        <Text style={styles.title}>PIN bestätigen</Text>
+        <Text style={styles.subtitle}>Bitte gib dieselbe PIN erneut ein.</Text>
+        <PinInput value={confirm} onChange={setConfirm} ariaLabel="PIN bestätigen" autoFocus />
+        {error && <Text style={styles.error}>{error}</Text>}
+        <Pressable
+          style={[styles.primary, confirm.length !== 6 && styles.disabled]}
+          disabled={confirm.length !== 6 || submitting}
+          onPress={() => {
+            if (pin !== confirm) {
+              setError('PIN stimmt nicht überein.');
+              setConfirm('');
+              return;
+            }
+            void runSetup(withRecovery);
+          }}
+        >
+          {submitting ? (
+            <ActivityIndicator color={colors.text} />
+          ) : (
+            <Text style={styles.primaryText}>PIN speichern</Text>
+          )}
+        </Pressable>
+        <Pressable onPress={() => setWithRecovery((v) => !v)} style={styles.secondary}>
+          <Text style={styles.secondaryText}>
+            {withRecovery
+              ? 'Recovery-Code überspringen (riskant)'
+              : 'Recovery-Code erzeugen (empfohlen)'}
+          </Text>
+        </Pressable>
+      </View>
+    );
+  }
+
+  if (step === 'recovery' && recoveryCode) {
+    return (
+      <ScrollView contentContainerStyle={styles.container}>
+        <Text style={styles.title}>Recovery-Code</Text>
+        <Text style={styles.subtitle}>
+          Notiere dir diesen Code an einem sicheren Ort. Du brauchst ihn, wenn du deine PIN
+          vergisst. Wir zeigen ihn dir nur EINMAL.
+        </Text>
+        <View style={styles.codeBox}>
+          <Text style={styles.codeText} selectable>
+            {recoveryCode}
+          </Text>
+        </View>
+        <Pressable
+          style={styles.primary}
+          onPress={async () => {
+            await refreshUserKeyState();
+            router.replace('/(app)/chats');
+          }}
+        >
+          <Text style={styles.primaryText}>Habe ich gespeichert</Text>
+        </Pressable>
+        <Pressable
+          style={styles.secondary}
+          onPress={() => {
+            Alert.alert(
+              'Sicher?',
+              'Ohne Recovery-Code verlierst du den Zugriff, wenn du die PIN vergisst.',
+              [
+                { text: 'Abbrechen', style: 'cancel' },
+                {
+                  text: 'Weiter ohne',
+                  style: 'destructive',
+                  onPress: async () => {
+                    await refreshUserKeyState();
+                    router.replace('/(app)/chats');
+                  },
+                },
+              ],
+            );
+          }}
+        >
+          <Text style={styles.secondaryText}>Überspringen</Text>
+        </Pressable>
+      </ScrollView>
+    );
+  }
+
+  return null;
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    padding: 24,
+    paddingTop: 64,
+    backgroundColor: colors.bg,
+    gap: 16,
+  },
+  title: { color: colors.text, fontSize: 24, fontWeight: '700' },
+  subtitle: { color: colors.textMuted, fontSize: 14, lineHeight: 20 },
+  error: { color: colors.danger, fontSize: 13 },
+  primary: {
+    backgroundColor: colors.accent,
+    paddingVertical: 14,
+    borderRadius: 12,
+    alignItems: 'center',
+    marginTop: 12,
+  },
+  primaryText: { color: colors.text, fontWeight: '700' },
+  disabled: { opacity: 0.5 },
+  secondary: { paddingVertical: 12, alignItems: 'center' },
+  secondaryText: { color: colors.accent, fontWeight: '600' },
+  codeBox: {
+    backgroundColor: colors.surface,
+    borderColor: colors.border,
+    borderWidth: 1,
+    padding: 16,
+    borderRadius: 12,
+  },
+  codeText: {
+    color: colors.text,
+    fontSize: 20,
+    fontFamily: 'Courier',
+    letterSpacing: 1.5,
+    textAlign: 'center',
+  },
+});

apps/mobile/app/(app)/unlock.tsx

@@ -0,0 +1,194 @@
+import { useRouter } from 'expo-router';
+import { useState } from 'react';
+import {
+  ActivityIndicator,
+  Pressable,
+  StyleSheet,
+  Text,
+  View,
+} from 'react-native';
+
+import { PinInput } from '../../components/PinInput';
+import { useAuth } from '../../lib/authContext';
+import { loadOrUnlockUserKey, resetIdentity } from '../../lib/userIdentity';
+import { colors } from '../../theme/colors';
+
+type Mode = 'pin' | 'recovery';
+
+export default function UnlockScreen() {
+  const router = useRouter();
+  const { userId, userKeyState, refreshUserKeyState } = useAuth();
+  const [mode, setMode] = useState<Mode>('pin');
+  const [pin, setPin] = useState('');
+  const [recovery, setRecovery] = useState('');
+  const [submitting, setSubmitting] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const locked =
+    userKeyState.status === 'needs-unlock' && userKeyState.lockedUntil !== null;
+  const hasRecovery =
+    userKeyState.status === 'needs-unlock' ? userKeyState.hasRecovery : false;
+
+  async function attempt(value: string, isRecoveryCode: boolean) {
+    if (!userId) return;
+    setSubmitting(true);
+    setError(null);
+    try {
+      const out = await loadOrUnlockUserKey({ userId, pin: value, isRecoveryCode });
+      if (out.kind === 'unlocked') {
+        await refreshUserKeyState();
+        router.replace('/(app)/chats');
+        return;
+      }
+      if (out.kind === 'locked') {
+        setError('Konto bis ' + new Date(out.lockedUntil).toLocaleString('de-DE') + ' gesperrt.');
+        await refreshUserKeyState();
+        return;
+      }
+      setError('Kein Identitäts-Datensatz auf dem Server.');
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Entsperren fehlgeschlagen');
+      if (isRecoveryCode) setRecovery('');
+      else setPin('');
+      await refreshUserKeyState();
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  async function handleReset() {
+    if (!userId) return;
+    setSubmitting(true);
+    setError(null);
+    try {
+      await resetIdentity({ userId, pin: '000000' });
+      await refreshUserKeyState();
+      router.replace('/(app)/setup');
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Reset fehlgeschlagen');
+    } finally {
+      setSubmitting(false);
+    }
+  }
+
+  return (
+    <View style={styles.container}>
+      <Text style={styles.title}>Netralax entsperren</Text>
+      <View style={styles.tabs}>
+        <Pressable
+          style={[styles.tab, mode === 'pin' && styles.tabActive]}
+          onPress={() => setMode('pin')}
+        >
+          <Text style={[styles.tabText, mode === 'pin' && styles.tabTextActive]}>PIN</Text>
+        </Pressable>
+        <Pressable
+          style={[styles.tab, mode === 'recovery' && styles.tabActive]}
+          disabled={!hasRecovery}
+          onPress={() => setMode('recovery')}
+        >
+          <Text style={[styles.tabText, mode === 'recovery' && styles.tabTextActive]}>
+            Recovery-Code
+          </Text>
+        </Pressable>
+      </View>
+
+      {mode === 'pin' ? (
+        <>
+          <PinInput
+            value={pin}
+            onChange={setPin}
+            ariaLabel="PIN eingeben"
+            autoFocus
+            disabled={locked || submitting}
+          />
+          <Pressable
+            style={[styles.primary, (pin.length !== 6 || locked || submitting) && styles.disabled]}
+            disabled={pin.length !== 6 || locked || submitting}
+            onPress={() => attempt(pin, false)}
+          >
+            {submitting ? (
+              <ActivityIndicator color={colors.text} />
+            ) : (
+              <Text style={styles.primaryText}>Entsperren</Text>
+            )}
+          </Pressable>
+        </>
+      ) : (
+        <>
+          <Text style={styles.subtitle}>Recovery-Code eingeben (mit oder ohne Bindestriche):</Text>
+          <Text style={styles.recoveryDisplay} selectable>
+            {recovery}
+          </Text>
+          <Pressable
+            style={[styles.primary, recovery.length === 0 && styles.disabled]}
+            disabled={recovery.length === 0 || submitting}
+            onPress={() => attempt(recovery, true)}
+          >
+            {submitting ? (
+              <ActivityIndicator color={colors.text} />
+            ) : (
+              <Text style={styles.primaryText}>Mit Recovery entsperren</Text>
+            )}
+          </Pressable>
+        </>
+      )}
+
+      {error && <Text style={styles.error}>{error}</Text>}
+
+      {locked && (
+        <Pressable style={styles.danger} onPress={handleReset}>
+          <Text style={styles.dangerText}>Identität zurücksetzen (alte Chats verloren)</Text>
+        </Pressable>
+      )}
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    backgroundColor: colors.bg,
+    paddingTop: 64,
+    paddingHorizontal: 24,
+    gap: 16,
+  },
+  title: { color: colors.text, fontSize: 22, fontWeight: '700' },
+  subtitle: { color: colors.textMuted, fontSize: 13 },
+  tabs: { flexDirection: 'row', gap: 8 },
+  tab: {
+    flex: 1,
+    paddingVertical: 10,
+    alignItems: 'center',
+    borderBottomWidth: 2,
+    borderBottomColor: colors.border,
+  },
+  tabActive: { borderBottomColor: colors.accent },
+  tabText: { color: colors.textMuted, fontWeight: '600' },
+  tabTextActive: { color: colors.text },
+  recoveryDisplay: {
+    color: colors.text,
+    fontFamily: 'Courier',
+    fontSize: 18,
+    letterSpacing: 1.5,
+    backgroundColor: colors.surface,
+    padding: 16,
+    borderRadius: 10,
+  },
+  primary: {
+    backgroundColor: colors.accent,
+    paddingVertical: 14,
+    borderRadius: 12,
+    alignItems: 'center',
+  },
+  primaryText: { color: colors.text, fontWeight: '700' },
+  disabled: { opacity: 0.5 },
+  danger: {
+    paddingVertical: 12,
+    alignItems: 'center',
+    borderColor: colors.danger,
+    borderWidth: 1,
+    borderRadius: 12,
+  },
+  dangerText: { color: colors.danger, fontWeight: '700' },
+  error: { color: colors.danger, fontSize: 13 },
+});

apps/mobile/app/_layout.tsx

@@ -1,34 +1,33 @@
-import { crypto } from '@chat-app/shared';
 import { Stack } from 'expo-router';
 import { StatusBar } from 'expo-status-bar';
 import { GestureHandlerRootView } from 'react-native-gesture-handler';
 import { SafeAreaProvider } from 'react-native-safe-area-context';
 
+import { AppBootstrap } from '../components/AppBootstrap';
 import { ErrorBoundary } from '../components/ErrorBoundary';
 import { IncomingCallModal } from '../components/IncomingCallModal';
 import { AuthProvider } from '../lib/authContext';
 import { CallProvider } from '../lib/callContext';
-import { createLibsodiumBackend } from '../lib/cryptoBackend';
-
-crypto.setCryptoBackend(createLibsodiumBackend());
 
 export default function RootLayout() {
   return (
     <GestureHandlerRootView style={{ flex: 1 }}>
       <SafeAreaProvider>
-        <ErrorBoundary>
-          <AuthProvider>
-            <CallProvider>
-              <StatusBar style="auto" />
-              <Stack screenOptions={{ headerShown: false }}>
-                <Stack.Screen name="index" />
-                <Stack.Screen name="(app)" />
-                <Stack.Screen name="auth/callback" />
-              </Stack>
-              <IncomingCallModal />
-            </CallProvider>
-          </AuthProvider>
-        </ErrorBoundary>
+        <AppBootstrap>
+          <ErrorBoundary>
+            <AuthProvider>
+              <CallProvider>
+                <StatusBar style="auto" />
+                <Stack screenOptions={{ headerShown: false }}>
+                  <Stack.Screen name="index" />
+                  <Stack.Screen name="(app)" />
+                  <Stack.Screen name="auth/callback" />
+                </Stack>
+                <IncomingCallModal />
+              </CallProvider>
+            </AuthProvider>
+          </ErrorBoundary>
+        </AppBootstrap>
       </SafeAreaProvider>
     </GestureHandlerRootView>
   );

apps/mobile/app/index.tsx

@@ -21,13 +21,13 @@ import { colors } from '../theme/colors';
 // they tap the email link and Expo Router routes the deep link to
 // app/auth/callback.tsx.
 export default function Landing() {
-  const { session, loading } = useAuth();
+  const { session, ready } = useAuth();
   const [email, setEmail] = useState('');
   const [submitting, setSubmitting] = useState(false);
   const [sent, setSent] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
-  if (loading) return null;
+  if (!ready) return null;
   if (session) return <Redirect href="/(app)/chats" />;
 
   async function handleSubmit() {

apps/mobile/components/AppBootstrap.tsx

@@ -0,0 +1,51 @@
+import { crypto } from '@chat-app/shared';
+import { type ReactNode, useEffect, useState } from 'react';
+
+import { createLibsodiumBackend } from '../lib/cryptoBackend';
+import { BootError } from './BootError';
+import { BootSplash } from './BootSplash';
+
+interface Props {
+  children: ReactNode;
+}
+
+// React Native exposes ErrorUtils on the global. The types ship with RN but
+// we cast defensively because the renderer used by Vitest does not.
+interface RNErrorUtils {
+  getGlobalHandler: () => (err: Error, isFatal?: boolean) => void;
+  setGlobalHandler: (handler: (err: Error, isFatal?: boolean) => void) => void;
+}
+
+// Initialises the crypto backend inside a useEffect (not at module-eval) so
+// any failure surfaces in the React tree. Also installs a global JS error
+// handler that routes unhandled throws to BootError; this catches errors
+// thrown during render (e.g. the lazy env proxy reading a missing var) that
+// would otherwise escape every per-screen ErrorBoundary.
+export function AppBootstrap({ children }: Props) {
+  const [error, setError] = useState<Error | null>(null);
+  const [ready, setReady] = useState(false);
+
+  useEffect(() => {
+    try {
+      crypto.setCryptoBackend(createLibsodiumBackend());
+      setReady(true);
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e : new Error(String(e)));
+    }
+  }, []);
+
+  useEffect(() => {
+    const eu = (globalThis as unknown as { ErrorUtils?: RNErrorUtils }).ErrorUtils;
+    if (!eu) return;
+    const prev = eu.getGlobalHandler();
+    eu.setGlobalHandler((err, isFatal) => {
+      prev?.(err, isFatal);
+      setError(err);
+    });
+    return () => eu.setGlobalHandler(prev);
+  }, []);
+
+  if (error) return <BootError error={error} />;
+  if (!ready) return <BootSplash />;
+  return <>{children}</>;
+}

apps/mobile/components/AttachmentImage.tsx

@@ -10,8 +10,6 @@ import { colors } from '../theme/colors';
 
 interface Props {
   handle: AttachmentHandle;
-  ownDeviceId: string;
-  ownPrivateKey: Uint8Array;
 }
 
 // Decrypts an encrypted image attachment on first mount and renders it

apps/mobile/components/BootError.tsx

@@ -0,0 +1,51 @@
+import { ScrollView, StyleSheet, Text, View } from 'react-native';
+
+import { colors } from '../theme/colors';
+
+interface Props {
+  error: Error;
+}
+
+// Last-resort fallback. Renders whenever AppBootstrap's init effect throws or
+// when the global JS error handler catches an unhandled exception. The
+// env-diagnostic line ("env-ok" / "env-missing") makes future bug reports
+// triageable from a single screenshot.
+export function BootError({ error }: Props) {
+  const envOk = Boolean(process.env.EXPO_PUBLIC_SUPABASE_URL);
+  return (
+    <ScrollView contentContainerStyle={styles.container}>
+      <Text style={styles.title}>App-Start fehlgeschlagen</Text>
+      <Text style={styles.message}>{error.message}</Text>
+      <View style={styles.diagnostic}>
+        <Text style={styles.diagnosticLabel}>EXPO_PUBLIC_SUPABASE_URL:</Text>
+        <Text style={[styles.diagnosticValue, envOk ? styles.ok : styles.bad]}>
+          {envOk ? 'env-ok' : 'env-missing'}
+        </Text>
+      </View>
+      {error.stack && <Text style={styles.stack}>{error.stack}</Text>}
+    </ScrollView>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flexGrow: 1,
+    backgroundColor: colors.bg,
+    padding: 24,
+    paddingTop: 64,
+    gap: 12,
+  },
+  title: { color: colors.text, fontSize: 20, fontWeight: '700' },
+  message: { color: colors.danger, fontSize: 14, lineHeight: 20 },
+  diagnostic: { flexDirection: 'row', gap: 8, marginTop: 8 },
+  diagnosticLabel: { color: colors.textMuted, fontSize: 12 },
+  diagnosticValue: { fontSize: 12, fontWeight: '700' },
+  ok: { color: colors.success },
+  bad: { color: colors.danger },
+  stack: {
+    color: colors.textDim,
+    fontSize: 11,
+    fontFamily: 'Courier',
+    marginTop: 16,
+  },
+});

apps/mobile/components/BootSplash.tsx

@@ -0,0 +1,22 @@
+import { ActivityIndicator, StyleSheet, View } from 'react-native';
+
+import { colors } from '../theme/colors';
+
+// Shown while AppBootstrap is initialising the crypto backend. Identical
+// background to the Expo splash so the handoff is invisible to the user.
+export function BootSplash() {
+  return (
+    <View style={styles.container}>
+      <ActivityIndicator color={colors.accent} />
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    alignItems: 'center',
+    justifyContent: 'center',
+    backgroundColor: colors.bg,
+  },
+});

apps/mobile/components/MessageBubble.tsx

@@ -15,7 +15,6 @@ interface Props {
   parentSenderName: string;
   reactions: MessageReaction[];
   myUserId: string | null;
-  ownDeviceId: string | null;
   ownPrivateKey: Uint8Array | null;
   onLongPress: () => void;
   onToggleReaction: (emoji: string) => void;
@@ -36,7 +35,6 @@ export function MessageBubble({
   parentSenderName,
   reactions,
   myUserId,
-  ownDeviceId,
   ownPrivateKey,
   onLongPress,
   onToggleReaction,
@@ -72,12 +70,8 @@ export function MessageBubble({
         ) : (
           <>
             {text.length > 0 && <Text style={styles.body}>{text}</Text>}
-            {firstImage && ownDeviceId && ownPrivateKey && (
-              <AttachmentImage
-                handle={firstImage}
-                ownDeviceId={ownDeviceId}
-                ownPrivateKey={ownPrivateKey}
-              />
+            {firstImage && ownPrivateKey && (
+              <AttachmentImage handle={firstImage} />
             )}
           </>
         )}

apps/mobile/components/PinInput.test.tsx

@@ -0,0 +1,31 @@
+import { fireEvent, render } from '@testing-library/react-native';
+import { describe, expect, it, vi } from 'vitest';
+
+import { PinInput } from './PinInput';
+
+describe('<PinInput>', () => {
+  it('appends digits to the underlying value and stops at length', () => {
+    const onChange = vi.fn();
+    const { getByTestId } = render(
+      <PinInput value="" onChange={onChange} length={6} ariaLabel="PIN" />,
+    );
+    fireEvent.changeText(getByTestId('pin-input'), '1234567890');
+    expect(onChange).toHaveBeenCalledWith('123456');
+  });
+
+  it('strips non-digits', () => {
+    const onChange = vi.fn();
+    const { getByTestId } = render(
+      <PinInput value="" onChange={onChange} length={6} ariaLabel="PIN" />,
+    );
+    fireEvent.changeText(getByTestId('pin-input'), '1a2b3c');
+    expect(onChange).toHaveBeenCalledWith('123');
+  });
+
+  it('renders one bullet per filled slot', () => {
+    const { getAllByText } = render(
+      <PinInput value="123" onChange={() => {}} length={6} ariaLabel="PIN" />,
+    );
+    expect(getAllByText('•').length).toBe(3);
+  });
+});

apps/mobile/components/PinInput.tsx

@@ -0,0 +1,95 @@
+import { useEffect, useRef } from 'react';
+import {
+  Pressable,
+  StyleSheet,
+  Text,
+  TextInput,
+  View,
+  type TextInput as TextInputType,
+} from 'react-native';
+
+import { colors } from '../theme/colors';
+
+interface Props {
+  value: string;
+  onChange: (next: string) => void;
+  length?: number;
+  autoFocus?: boolean;
+  disabled?: boolean;
+  ariaLabel: string;
+  onSubmit?: () => void;
+}
+
+// Six-slot numeric PIN entry. The actual input is an invisible TextInput
+// that captures the numeric keyboard; visible slots render bullets when
+// filled. Tapping anywhere on the row re-focuses the input.
+export function PinInput({
+  value,
+  onChange,
+  length = 6,
+  autoFocus,
+  disabled,
+  ariaLabel,
+  onSubmit,
+}: Props) {
+  const ref = useRef<TextInputType | null>(null);
+  useEffect(() => {
+    if (autoFocus) ref.current?.focus();
+  }, [autoFocus]);
+  return (
+    <Pressable onPress={() => ref.current?.focus()} style={styles.row}>
+      <TextInput
+        ref={ref}
+        testID="pin-input"
+        accessibilityLabel={ariaLabel}
+        keyboardType="numeric"
+        textContentType="oneTimeCode"
+        autoComplete="one-time-code"
+        maxLength={length}
+        editable={!disabled}
+        value={value}
+        onChangeText={(t) => onChange(t.replace(/\D/g, '').slice(0, length))}
+        onSubmitEditing={() => {
+          if (value.length === length) onSubmit?.();
+        }}
+        style={styles.hidden}
+      />
+      <View style={styles.slots}>
+        {Array.from({ length }).map((_, i) => {
+          const filled = i < value.length;
+          return (
+            <View key={i} style={[styles.slot, filled && styles.slotFilled]}>
+              {filled && <Text style={styles.bullet}>•</Text>}
+            </View>
+          );
+        })}
+      </View>
+    </Pressable>
+  );
+}
+
+const styles = StyleSheet.create({
+  row: { alignItems: 'center' },
+  hidden: {
+    position: 'absolute',
+    width: 1,
+    height: 1,
+    opacity: 0,
+  },
+  slots: { flexDirection: 'row', gap: 8 },
+  slot: {
+    width: 40,
+    height: 48,
+    borderRadius: 10,
+    borderWidth: 1,
+    borderColor: colors.border,
+    alignItems: 'center',
+    justifyContent: 'center',
+    backgroundColor: colors.surface,
+  },
+  slotFilled: {
+    borderColor: colors.accent,
+    backgroundColor: colors.bg,
+  },
+  bullet: { color: colors.text, fontSize: 22 },
+});

apps/mobile/lib/authContext.tsx

@@ -1,23 +1,31 @@
 import type { Session, User } from '@supabase/supabase-js';
-import { auth, crypto } from '@chat-app/shared';
-import type { DeviceRecord } from '@chat-app/shared/auth';
-import { createContext, useCallback, useContext, useEffect, useState } from 'react';
-import { Platform } from 'react-native';
+import { fetchUserKeyBlob } from '@chat-app/shared/auth';
+import {
+  type ReactNode,
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useState,
+} from 'react';
 
-import { secretStore } from './secretStore';
 import { supabase } from './supabase';
+import { cachedUserKey, ensureLegacyMigrated } from './userIdentity';
 
-// Locally-stored secrets keyed by stable names. Mirrors the desktop
-// convention so the migration tests (later) can compare snapshots.
-const KEY_DEVICE_ID = 'device.id';
-const KEY_DEVICE_PRIVKEY = 'device.privateKey';
+export type UserKeyState =
+  | { status: 'loading' }
+  | { status: 'needs-setup' }
+  | { status: 'needs-unlock'; lockedUntil: string | null; hasRecovery: boolean }
+  | { status: 'unlocked' };
 
 interface AuthContextValue {
   session: Session | null;
   user: User | null;
-  device: DeviceRecord | null;
+  userId: string | null;
   ownPrivateKey: Uint8Array | null;
-  loading: boolean;
+  userKeyState: UserKeyState;
+  ready: boolean;
+  refreshUserKeyState: () => Promise<void>;
   signOut: () => Promise<void>;
 }
 
@@ -29,44 +37,48 @@ export function useAuth(): AuthContextValue {
   return v;
 }
 
-export function AuthProvider({ children }: { children: React.ReactNode }) {
+export function AuthProvider({ children }: { children: ReactNode }) {
   const [session, setSession] = useState<Session | null>(null);
-  const [device, setDevice] = useState<DeviceRecord | null>(null);
   const [ownPrivateKey, setOwnPrivateKey] = useState<Uint8Array | null>(null);
-  const [loading, setLoading] = useState(true);
+  const [userKeyState, setUserKeyState] = useState<UserKeyState>({ status: 'loading' });
+  const [ready, setReady] = useState(false);
 
-  // Resolve or create the device record for this install given an active
-  // session. Stores the private key in expo-secure-store on first run.
-  const ensureDevice = useCallback(async (_currentSession: Session): Promise<void> => {
-    const savedDeviceId = await secretStore.getSecret(KEY_DEVICE_ID);
-    const savedPrivKey = await secretStore.getSecret(KEY_DEVICE_PRIVKEY);
-
-    if (savedDeviceId && savedPrivKey) {
-      const devices = await auth.listOwnDevices(supabase);
-      const deviceIdStr = new TextDecoder().decode(savedDeviceId);
-      const match = devices.find((d) => d.id === deviceIdStr);
-      if (match) {
-        setDevice(match);
-        setOwnPrivateKey(savedPrivKey);
-        return;
-      }
-      // Stored id no longer matches any device on the server (revoked,
-      // wiped). Fall through to register a fresh one.
+  const refreshUserKeyState = useCallback(async () => {
+    const s = session;
+    if (!s) {
+      setUserKeyState({ status: 'loading' });
+      setOwnPrivateKey(null);
+      return;
     }
-
-    const backend = crypto.getCryptoBackend();
-    const kp = backend.generateKeyPair();
-    const platform = Platform.OS === 'ios' ? 'ios' : Platform.OS === 'android' ? 'android' : 'linux';
-    const record = await auth.registerDevice(supabase, {
-      name: `Netralax Mobile (${Platform.OS})`,
-      platform,
-      publicKey: kp.publicKey,
+    setUserKeyState({ status: 'loading' });
+    const cached = await cachedUserKey(s.user.id);
+    if (cached) {
+      setOwnPrivateKey(cached);
+      setUserKeyState({ status: 'unlocked' });
+      void ensureLegacyMigrated(s.user.id).catch((err) => {
+        console.warn('legacy migration on auth-resume failed', err);
+      });
+      return;
+    }
+    const blob = await fetchUserKeyBlob(supabase, s.user.id);
+    if (!blob || !blob.exists) {
+      setUserKeyState({ status: 'needs-setup' });
+      return;
+    }
+    if (blob.locked) {
+      setUserKeyState({
+        status: 'needs-unlock',
+        lockedUntil: blob.lockedUntil,
+        hasRecovery: false,
+      });
+      return;
+    }
+    setUserKeyState({
+      status: 'needs-unlock',
+      lockedUntil: null,
+      hasRecovery: blob.recoverySealedPrivateKey !== null,
     });
-    await secretStore.setSecret(KEY_DEVICE_ID, new TextEncoder().encode(record.id));
-    await secretStore.setSecret(KEY_DEVICE_PRIVKEY, kp.privateKey);
-    setDevice(record);
-    setOwnPrivateKey(kp.privateKey);
-  }, []);
+  }, [session]);
 
   useEffect(() => {
     let cancelled = false;
@@ -74,48 +86,43 @@ export function AuthProvider({ children }: { children: React.ReactNode }) {
       const { data } = await supabase.auth.getSession();
       if (cancelled) return;
       setSession(data.session);
-      if (data.session) {
-        try {
-          await ensureDevice(data.session);
-        } catch (err) {
-          console.warn('[auth] ensureDevice failed', err);
-        }
-      }
-      setLoading(false);
+      setReady(true);
     })();
-
     const { data: sub } = supabase.auth.onAuthStateChange((_event, nextSession) => {
       setSession(nextSession);
+      setReady(true);
       if (!nextSession) {
-        setDevice(null);
         setOwnPrivateKey(null);
-      } else {
-        void ensureDevice(nextSession).catch((err) =>
-          console.warn('[auth] ensureDevice (state change) failed', err),
-        );
+        setUserKeyState({ status: 'loading' });
       }
     });
-
     return () => {
       cancelled = true;
       sub.subscription.unsubscribe();
     };
-  }, [ensureDevice]);
+  }, []);
 
-  const signOut = useCallback(async (): Promise<void> => {
+  useEffect(() => {
+    void refreshUserKeyState().catch((err) => {
+      console.warn('refreshUserKeyState failed', err);
+      setUserKeyState({ status: 'needs-setup' });
+    });
+  }, [session, refreshUserKeyState]);
+
+  const signOut = useCallback(async () => {
     await supabase.auth.signOut();
-    await secretStore.removeSecret(KEY_DEVICE_ID);
-    await secretStore.removeSecret(KEY_DEVICE_PRIVKEY);
-    setDevice(null);
     setOwnPrivateKey(null);
+    setUserKeyState({ status: 'loading' });
   }, []);
 
   const value: AuthContextValue = {
     session,
     user: session?.user ?? null,
-    device,
+    userId: session?.user.id ?? null,
     ownPrivateKey,
-    loading,
+    userKeyState,
+    ready,
+    refreshUserKeyState,
     signOut,
   };
   return <Ctx.Provider value={value}>{children}</Ctx.Provider>;

apps/mobile/lib/cryptoBackend.ts

@@ -24,5 +24,13 @@ export function createLibsodiumBackend(): CryptoBackend {
       s.crypto_box_open_easy(ciphertext, nonce, senderPublicKey, recipientPrivateKey),
     secretbox: (plaintext, nonce, key) => s.crypto_secretbox_easy(plaintext, nonce, key),
     secretboxOpen: (ciphertext, nonce, key) => s.crypto_secretbox_open_easy(ciphertext, nonce, key),
+    pwhashConsts: {
+      OPSLIMIT_MODERATE: s.crypto_pwhash_OPSLIMIT_MODERATE,
+      MEMLIMIT_MODERATE: s.crypto_pwhash_MEMLIMIT_MODERATE,
+      ALG_ARGON2ID13: s.crypto_pwhash_ALG_ARGON2ID13,
+    },
+    pwhash: (outLen, password, salt, opslimit, memlimit, alg) =>
+      s.crypto_pwhash(outLen, password, salt, opslimit, memlimit, alg),
+    scalarMultBase: (priv) => s.crypto_scalarmult_base(priv),
   };
 }

apps/mobile/lib/env.test.ts

@@ -0,0 +1,30 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+describe('mobile env (lazy proxy)', () => {
+  beforeEach(() => {
+    vi.resetModules();
+    delete process.env.EXPO_PUBLIC_SUPABASE_URL;
+    delete process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY;
+    delete process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL;
+  });
+
+  it('importing the module does NOT throw when required vars are missing', async () => {
+    await expect(import('./env')).resolves.toBeTruthy();
+  });
+
+  it('reading a property with no env set throws a clear error', async () => {
+    const mod = await import('./env');
+    expect(() => mod.env.supabaseUrl).toThrowError(
+      /Missing required env var EXPO_PUBLIC_SUPABASE_URL/,
+    );
+  });
+
+  it('reading a property after setting env returns the value and memoises', async () => {
+    process.env.EXPO_PUBLIC_SUPABASE_URL = 'https://example.supabase.co';
+    process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY = 'anon-123';
+    const mod = await import('./env');
+    expect(mod.env.supabaseUrl).toBe('https://example.supabase.co');
+    expect(mod.env.supabaseAnonKey).toBe('anon-123');
+    expect(mod.env.authRedirectUrl).toBe('netralax://auth/callback');
+  });
+});

apps/mobile/lib/env.ts

@@ -1,19 +1,41 @@
-// EXPO_PUBLIC_* vars are inlined at bundle time by Expo's Babel plugin.
-// We pull them through a single typed module so a missing var is a loud
-// startup error rather than a confusing Supabase 401 later.
+// EXPO_PUBLIC_* vars are inlined at bundle time by Expo's Babel plugin (or
+// shipped via EAS Secrets for EAS builds — see apps/mobile/README.md).
+// We pull them through a Proxy so missing vars throw on first READ, not at
+// module-eval time. That keeps the throw inside the React tree where the
+// <BootError> boundary can render it as a readable screen instead of a blank
+// white window.
 
 function required(name: string): string {
   const v = process.env[name];
   if (!v || v.length === 0) {
     throw new Error(
-      'Missing required env var ' + name + '. Set it in apps/mobile/.env.local — see .env.example.',
+      'Missing required env var ' + name +
+        '. Set it via `eas secret:create --scope project --name ' + name +
+        ' --value ...` or in apps/mobile/.env.local for local dev (see .env.example).',
     );
   }
   return v;
 }
 
-export const env = {
-  supabaseUrl: required('EXPO_PUBLIC_SUPABASE_URL'),
-  supabaseAnonKey: required('EXPO_PUBLIC_SUPABASE_ANON_KEY'),
-  authRedirectUrl: process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL ?? 'netralax://auth/callback',
-} as const;
+interface EnvShape {
+  supabaseUrl: string;
+  supabaseAnonKey: string;
+  authRedirectUrl: string;
+}
+
+function readEnv(): EnvShape {
+  return {
+    supabaseUrl: required('EXPO_PUBLIC_SUPABASE_URL'),
+    supabaseAnonKey: required('EXPO_PUBLIC_SUPABASE_ANON_KEY'),
+    authRedirectUrl: process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL ?? 'netralax://auth/callback',
+  };
+}
+
+let cached: EnvShape | null = null;
+
+export const env: EnvShape = new Proxy({} as EnvShape, {
+  get(_target, key: string | symbol): unknown {
+    cached ??= readEnv();
+    return cached[key as keyof EnvShape];
+  },
+});

apps/mobile/lib/legacyDeviceVault.ts

@@ -0,0 +1,9 @@
+import { secretStore } from './secretStore';
+
+// During the migration window the orchestrator probes SecureStore for legacy
+// per-device private keys. We keep this read-only — never write — so a future
+// reset can safely wipe the new chatapp.userpriv.* slot without affecting
+// pre-existing legacy entries.
+export function legacyDeviceKey(userId: string, deviceId: string): Promise<Uint8Array | null> {
+  return secretStore.getSecret('chatapp.priv.' + userId + '.' + deviceId);
+}

apps/mobile/lib/userIdentity.test.ts

@@ -0,0 +1,61 @@
+import { crypto } from '@chat-app/shared';
+import { makeWasmTestBackend } from '@chat-app/shared/crypto/testBackend';
+import { beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
+
+// We mock react-native modules so this Vitest file can run in Node without
+// loading native code. The mocks live next to the test for clarity.
+vi.mock('expo-secure-store', () => {
+  const store = new Map<string, string>();
+  return {
+    getItemAsync: vi.fn(async (k: string) => store.get(k) ?? null),
+    setItemAsync: vi.fn(async (k: string, v: string) => {
+      store.set(k, v);
+    }),
+    deleteItemAsync: vi.fn(async (k: string) => {
+      store.delete(k);
+    }),
+  };
+});
+
+const rpcImpl = vi.fn();
+vi.mock('./supabase', () => ({
+  supabase: {
+    rpc: (name: string, params: unknown) => rpcImpl(name, params),
+    from: () => ({
+      select: () => ({ in: () => Promise.resolve({ data: [], error: null }) }),
+    }),
+  },
+}));
+
+beforeAll(async () => {
+  crypto.setCryptoBackend(await makeWasmTestBackend());
+});
+
+beforeEach(() => {
+  rpcImpl.mockReset();
+});
+
+describe('mobile userIdentity', () => {
+  it('setupNewUserIdentity uploads + caches', async () => {
+    rpcImpl.mockResolvedValue({ data: 0, error: null });
+    const { setupNewUserIdentity, cachedUserKey } = await import('./userIdentity');
+    const out = await setupNewUserIdentity({
+      userId: 'user-1',
+      pin: '123456',
+      withRecovery: true,
+    });
+    expect(out.publicKey.length).toBe(32);
+    expect(out.recoveryCode).toMatch(/^[A-Z0-9-]+$/);
+    const cached = await cachedUserKey('user-1');
+    expect(cached).not.toBeNull();
+    expect(cached!.length).toBe(32);
+    expect(rpcImpl).toHaveBeenCalledWith('upsert_user_key', expect.any(Object));
+  });
+
+  it('loadOrUnlockUserKey returns `missing` when blob does not exist', async () => {
+    rpcImpl.mockResolvedValue({ data: { exists: false }, error: null });
+    const { loadOrUnlockUserKey } = await import('./userIdentity');
+    const out = await loadOrUnlockUserKey({ userId: 'user-2', pin: '000000' });
+    expect(out.kind).toBe('missing');
+  });
+});

apps/mobile/lib/userIdentity.ts

@@ -0,0 +1,266 @@
+import { migrateOwnLegacyBundles } from '@chat-app/shared/chat';
+import {
+  fetchUserKeyBlob,
+  listOwnDevices,
+  recordPinAttempt,
+  resetUserKey,
+  tryUnlockUserKey,
+  uploadUserKeyBlob,
+} from '@chat-app/shared/auth';
+import {
+  generateRecoveryCode,
+  generateUserKeyPair,
+  getCryptoBackend,
+  normalizeRecoveryCode,
+  openUserKey,
+  sealUserKey,
+} from '@chat-app/shared/crypto';
+
+import { legacyDeviceKey } from './legacyDeviceVault';
+import { secretStore } from './secretStore';
+import { supabase } from './supabase';
+
+const cacheKey = (userId: string) => 'chatapp.userpriv.' + userId;
+
+export interface SetupParams {
+  userId: string;
+  pin: string;
+  withRecovery: boolean;
+}
+export interface SetupResult {
+  publicKey: Uint8Array;
+  recoveryCode: string | null;
+}
+
+export async function setupNewUserIdentity(p: SetupParams): Promise<SetupResult> {
+  const kp = await generateUserKeyPair();
+  const sealed = await sealUserKey({ privateKey: kp.privateKey, pin: p.pin });
+  let recoveryCode: string | null = null;
+  let recoverySealed: { sealedPrivateKey: Uint8Array; salt: Uint8Array } | null = null;
+  if (p.withRecovery) {
+    recoveryCode = await generateRecoveryCode();
+    const r = await sealUserKey({
+      privateKey: kp.privateKey,
+      pin: normalizeRecoveryCode(recoveryCode),
+    });
+    recoverySealed = { sealedPrivateKey: r.sealedPrivateKey, salt: r.salt };
+  }
+  await uploadUserKeyBlob(supabase, {
+    userId: p.userId,
+    publicKey: kp.publicKey,
+    sealedPrivateKey: sealed.sealedPrivateKey,
+    salt: sealed.salt,
+    kdfParams: sealed.kdfParams,
+    recoverySealedPrivateKey: recoverySealed?.sealedPrivateKey ?? null,
+    recoverySalt: recoverySealed?.salt ?? null,
+  });
+  await secretStore.setSecret(cacheKey(p.userId), kp.privateKey);
+  void ensureLegacyMigrated(p.userId).catch((err) => {
+    console.warn('legacy conv-key migration failed', err);
+  });
+  return { publicKey: kp.publicKey, recoveryCode };
+}
+
+export interface UnlockParams {
+  userId: string;
+  pin: string;
+  isRecoveryCode?: boolean;
+}
+
+export type UnlockOutcome =
+  | { kind: 'unlocked' }
+  | { kind: 'locked'; lockedUntil: string }
+  | { kind: 'missing' };
+
+export async function loadOrUnlockUserKey(p: UnlockParams): Promise<UnlockOutcome> {
+  const remote = await tryUnlockUserKey(supabase, p.userId);
+  if (!remote.exists) return { kind: 'missing' };
+  if (remote.locked) return { kind: 'locked', lockedUntil: remote.lockedUntil };
+  const secret = p.isRecoveryCode ? normalizeRecoveryCode(p.pin) : p.pin;
+  const sealed = p.isRecoveryCode ? remote.recoverySealedPrivateKey : remote.sealedPrivateKey;
+  const salt = p.isRecoveryCode ? remote.recoverySalt : remote.salt;
+  if (!sealed || !salt) throw new Error('no recovery blob configured');
+  let priv: Uint8Array;
+  try {
+    priv = await openUserKey({ sealed, pin: secret, salt, kdfParams: remote.kdfParams });
+  } catch (err) {
+    await recordPinAttempt(supabase, p.userId, false, p.isRecoveryCode === true).catch(() => {});
+    throw err;
+  }
+  await recordPinAttempt(supabase, p.userId, true, p.isRecoveryCode === true).catch(() => {});
+  await secretStore.setSecret(cacheKey(p.userId), priv);
+  void ensureLegacyMigrated(p.userId).catch((err) => {
+    console.warn('legacy conv-key migration failed', err);
+  });
+  return { kind: 'unlocked' };
+}
+
+export async function cachedUserKey(userId: string): Promise<Uint8Array | null> {
+  return secretStore.getSecret(cacheKey(userId));
+}
+
+export async function clearUserKeyCache(userId: string): Promise<void> {
+  await secretStore.removeSecret(cacheKey(userId));
+}
+
+export async function userKeyExistsRemotely(userId: string): Promise<boolean> {
+  const blob = await fetchUserKeyBlob(supabase, userId);
+  return blob !== null;
+}
+
+export async function changePin(params: {
+  userId: string;
+  oldPin: string;
+  newPin: string;
+}): Promise<void> {
+  const cached = await cachedUserKey(params.userId);
+  if (!cached) throw new Error('user key not cached locally — re-login required');
+  const fresh = await sealUserKey({ privateKey: cached, pin: params.newPin });
+  await uploadUserKeyBlob(supabase, {
+    userId: params.userId,
+    publicKey: getCryptoBackend().scalarMultBase(cached),
+    sealedPrivateKey: fresh.sealedPrivateKey,
+    salt: fresh.salt,
+    kdfParams: fresh.kdfParams,
+  });
+  void params.oldPin; // cached key already proves old PIN was correct
+}
+
+export async function regenerateRecoveryCode(params: { userId: string }): Promise<string> {
+  const cached = await cachedUserKey(params.userId);
+  if (!cached) throw new Error('user key not cached locally');
+  const blob = await fetchUserKeyBlob(supabase, params.userId);
+  if (!blob || !blob.exists || blob.locked) {
+    throw new Error('cannot regenerate recovery while locked');
+  }
+  const recoveryCode = await generateRecoveryCode();
+  const sealed = await sealUserKey({
+    privateKey: cached,
+    pin: normalizeRecoveryCode(recoveryCode),
+  });
+  await uploadUserKeyBlob(supabase, {
+    userId: params.userId,
+    publicKey: getCryptoBackend().scalarMultBase(cached),
+    sealedPrivateKey: blob.sealedPrivateKey,
+    salt: blob.salt,
+    kdfParams: blob.kdfParams,
+    recoverySealedPrivateKey: sealed.sealedPrivateKey,
+    recoverySalt: sealed.salt,
+  });
+  return recoveryCode;
+}
+
+export async function resetIdentity(params: {
+  userId: string;
+  pin: string;
+}): Promise<string> {
+  await clearUserKeyCache(params.userId);
+  await resetUserKey(supabase, {
+    userId: params.userId,
+    publicKey: new Uint8Array(32),
+    sealedPrivateKey: new Uint8Array(40),
+    salt: new Uint8Array(16),
+    kdfParams: { algo: 'argon2id', preset: 'moderate', opslimit: 1, memlimit: 1 },
+  });
+  const setup = await setupNewUserIdentity({
+    userId: params.userId,
+    pin: params.pin,
+    withRecovery: true,
+  });
+  return setup.recoveryCode ?? '';
+}
+
+export interface LegacyMigrationReport {
+  serverDevices: number;
+  strongholdKeysFromServerDevices: number;
+  strongholdKeysFromBundleScan: number;
+  attempted: number;
+  migrated: number;
+  noStrongholdKey: number;
+  decryptFailed: number;
+  rpcFailed: number;
+}
+
+export async function ensureLegacyMigrated(userId: string): Promise<LegacyMigrationReport | null> {
+  const priv = await cachedUserKey(userId);
+  if (!priv) return null;
+  const pub = getCryptoBackend().scalarMultBase(priv);
+  return runLegacyMigration(userId, priv, pub);
+}
+
+export async function retryLegacyMigration(userId: string): Promise<LegacyMigrationReport> {
+  const priv = await cachedUserKey(userId);
+  if (!priv) throw new Error('user key not cached locally — re-login required');
+  const pub = getCryptoBackend().scalarMultBase(priv);
+  return runLegacyMigration(userId, priv, pub);
+}
+
+async function runLegacyMigration(
+  userId: string,
+  ownNewPriv: Uint8Array,
+  ownNewPub: Uint8Array,
+): Promise<LegacyMigrationReport> {
+  const report: LegacyMigrationReport = {
+    serverDevices: 0,
+    strongholdKeysFromServerDevices: 0,
+    strongholdKeysFromBundleScan: 0,
+    attempted: 0,
+    migrated: 0,
+    noStrongholdKey: 0,
+    decryptFailed: 0,
+    rpcFailed: 0,
+  };
+
+  const devices = await listOwnDevices(supabase);
+  report.serverDevices = devices.length;
+  const ownLegacyDevicePrivateKeys: Record<string, Uint8Array> = {};
+
+  for (const d of devices) {
+    const k = await legacyDeviceKey(userId, d.id);
+    if (k) ownLegacyDevicePrivateKeys[d.id] = k;
+  }
+  report.strongholdKeysFromServerDevices = Object.keys(ownLegacyDevicePrivateKeys).length;
+
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const { data: scanRowsRaw } = await (supabase as any)
+    .from('conversation_keys')
+    .select('recipient_device_id')
+    .is('recipient_user_id', null)
+    .not('recipient_device_id', 'is', null);
+  const scanIds = Array.from(
+    new Set(
+      ((scanRowsRaw ?? []) as { recipient_device_id: string }[])
+        .map((r) => r.recipient_device_id)
+        .filter((id): id is string => Boolean(id)),
+    ),
+  );
+  for (const id of scanIds) {
+    if (ownLegacyDevicePrivateKeys[id]) continue;
+    const k = await legacyDeviceKey(userId, id);
+    if (k) {
+      ownLegacyDevicePrivateKeys[id] = k;
+      report.strongholdKeysFromBundleScan += 1;
+    }
+  }
+
+  const ids = Object.keys(ownLegacyDevicePrivateKeys);
+  if (ids.length === 0) {
+    console.warn('[crypto-migration] no legacy private keys in vault — nothing to migrate');
+    return report;
+  }
+
+  const result = await migrateOwnLegacyBundles({
+    client: supabase,
+    ownUserId: userId,
+    ownNewPublicKey: ownNewPub,
+    ownNewPrivateKey: ownNewPriv,
+    ownLegacyDeviceIds: ids,
+    ownLegacyDevicePrivateKeys,
+  });
+  report.attempted = result.attempted;
+  report.migrated = result.migratedConversations;
+  report.noStrongholdKey = result.noStrongholdKey;
+  report.decryptFailed = result.decryptFailed;
+  report.rpcFailed = result.rpcFailed;
+  return report;
+}

apps/mobile/package.json

@@ -15,7 +15,8 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
-    "clean": "rm -rf .expo node_modules/.cache .turbo *.tsbuildinfo"
+    "clean": "rm -rf .expo node_modules/.cache .turbo *.tsbuildinfo",
+    "check:env": "node scripts/check-env.mjs"
   },
   "dependencies": {
     "@babel/runtime": "^7.29.2",
@@ -48,6 +49,9 @@
   },
   "devDependencies": {
     "@babel/core": "^7.25.0",
-    "@types/react": "~18.3.12"
+    "@testing-library/react-native": "^12.9.0",
+    "@types/react": "~18.3.12",
+    "jsdom": "^29.1.1",
+    "react-test-renderer": "18.3.1"
   }
 }

apps/mobile/scripts/check-env.mjs

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+// Compares apps/mobile/.env.example with .env.local. Surfaces missing keys
+// so an onboarding dev doesn't ship a build that white-screens.
+
+import { existsSync, readFileSync } from 'node:fs';
+import { dirname, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const here = dirname(fileURLToPath(import.meta.url));
+const mobileRoot = resolve(here, '..');
+const examplePath = resolve(mobileRoot, '.env.example');
+const localPath = resolve(mobileRoot, '.env.local');
+
+if (!existsSync(localPath)) {
+  console.error('No .env.local found at ' + localPath);
+  console.error('Copy .env.example to .env.local and fill in values.');
+  process.exit(1);
+}
+
+function keysOf(path) {
+  return new Set(
+    readFileSync(path, 'utf8')
+      .split('\n')
+      .map((line) => line.trim())
+      .filter((line) => line.length > 0 && !line.startsWith('#'))
+      .map((line) => line.split('=', 1)[0]),
+  );
+}
+
+const exampleKeys = keysOf(examplePath);
+const localKeys = keysOf(localPath);
+const missing = [...exampleKeys].filter((k) => !localKeys.has(k));
+
+if (missing.length > 0) {
+  console.error('Missing keys in .env.local: ' + missing.join(', '));
+  process.exit(1);
+}
+console.log('env-ok: all .env.example keys present in .env.local');

apps/mobile/vitest.config.ts

@@ -0,0 +1,34 @@
+import { defineConfig } from 'vitest/config';
+import { fileURLToPath } from 'node:url';
+
+const shimPath = fileURLToPath(new URL('./vitest.rn-shim.ts', import.meta.url));
+
+// Vitest cannot transform React Native's Flow-typed source. We redirect
+// every `react-native` reference to a minimal host-component shim
+// (`vitest.rn-shim.ts`) so @testing-library/react-native v12 + jsdom can
+// render the few primitives PinInput uses.
+//
+// Two interception layers are needed:
+//   1. resolve.alias  — covers ESM imports vite sees during transformation
+//      of inlined dependencies (e.g. when @testing-library/react-native
+//      goes through vite's pipeline because of `server.deps.inline`).
+//   2. setupFiles patches Module._resolveFilename so any pure-CJS
+//      `require("react-native")` that escapes vite also lands on the shim.
+export default defineConfig({
+  test: {
+    environment: 'jsdom',
+    include: ['**/*.test.ts', '**/*.test.tsx'],
+    setupFiles: ['./vitest.setup.ts'],
+    server: {
+      deps: {
+        inline: [/@testing-library\/react-native/],
+      },
+    },
+  },
+  resolve: {
+    alias: [
+      { find: /^react-native$/, replacement: shimPath },
+      { find: /^react-native\/(.*)$/, replacement: shimPath },
+    ],
+  },
+});

apps/mobile/vitest.rn-shim.ts

@@ -0,0 +1,84 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+// Minimal `react-native` surface used by vitest tests. Each visible
+// primitive is a forwardRef component that renders a lower-case React
+// element so react-test-renderer treats it as a regular host node, and
+// @testing-library/react-native's queries can traverse the tree.
+// The shim is loaded by Module._resolveFilename in vitest.setup.ts.
+import * as React from 'react';
+
+function makeHost(name: string) {
+  const C: any = React.forwardRef(function HostComponent(
+    props: Record<string, unknown>,
+    ref: unknown,
+  ) {
+    return React.createElement(name, { ...props, ref });
+  });
+  C.displayName = name;
+  return C;
+}
+
+export const View = makeHost('View');
+export const Text = makeHost('Text');
+export const TextInput = makeHost('TextInput');
+export const Pressable = makeHost('Pressable');
+export const Image = makeHost('Image');
+export const ScrollView = makeHost('ScrollView');
+export const Modal = makeHost('Modal');
+export const Switch = makeHost('Switch');
+
+export const Platform = { OS: 'test', select: (m: any) => m.default ?? m.test ?? null };
+
+export const StyleSheet = {
+  create<T extends Record<string, unknown>>(s: T): T {
+    return s;
+  },
+  flatten(s: unknown): unknown {
+    if (Array.isArray(s)) {
+      const flat: Record<string, unknown> = {};
+      for (const part of s) Object.assign(flat, part ?? {});
+      return flat;
+    }
+    return s ?? {};
+  },
+  hairlineWidth: 1,
+  absoluteFill: {},
+  absoluteFillObject: {},
+};
+
+export const Dimensions = { get: () => ({ width: 360, height: 640 }) };
+export const NativeModules: Record<string, unknown> = {};
+export const Animated = { View, Text, Image, createAnimatedComponent: (c: unknown) => c };
+export const Linking = { openURL: async () => undefined };
+export const Alert = { alert: () => undefined };
+export const Appearance = { getColorScheme: () => 'dark' };
+export const AccessibilityInfo = {
+  isScreenReaderEnabled: async () => false,
+  addEventListener: () => ({ remove: () => undefined }),
+};
+export const PixelRatio = { get: () => 2 };
+export const Keyboard = { dismiss: () => undefined };
+export const useWindowDimensions = () => ({ width: 360, height: 640 });
+
+const defaultExport = {
+  View,
+  Text,
+  TextInput,
+  Pressable,
+  Image,
+  ScrollView,
+  Modal,
+  Switch,
+  Platform,
+  StyleSheet,
+  Dimensions,
+  NativeModules,
+  Animated,
+  Linking,
+  Alert,
+  Appearance,
+  AccessibilityInfo,
+  PixelRatio,
+  Keyboard,
+  useWindowDimensions,
+};
+export default defaultExport;

apps/mobile/vitest.setup.ts

@@ -0,0 +1,25 @@
+// Vitest cannot transform React Native's Flow-typed source. We monkey-patch
+// Node's CommonJS resolver so every bare `react-native` request returns our
+// minimal host-component shim. This file is referenced by `setupFiles` in
+// vitest.config.ts and runs before any test file imports execute.
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const Module = require('node:module');
+import * as path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const shimPath = path.join(here, 'vitest.rn-shim.ts');
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const originalResolve = (Module as any)._resolveFilename;
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+(Module as any)._resolveFilename = function patched(
+  request: string,
+  parent: unknown,
+  ...rest: unknown[]
+): string {
+  if (request === 'react-native' || request.startsWith('react-native/')) {
+    return shimPath;
+  }
+  return originalResolve.call(this, request, parent, ...rest);
+};

docs/superpowers/plans/2026-05-16-android-whitescreen-rca.md

@@ -0,0 +1,779 @@
+# Android White-Screen RCA — Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Identify and fix the cause of the Android white-screen-after-install on the mobile build, and ship defense-in-depth so the next boot-time failure renders a readable error screen instead of a blank window.
+
+**Architecture:** Wire EXPO_PUBLIC_* into EAS builds via EAS Secrets (the leading hypothesis). Make `env.ts` lazy so missing variables throw inside React. Add an `<AppBootstrap>` boundary inside `_layout.tsx` that initialises the crypto backend in a `useEffect`, renders a splash while loading, and routes any error to a `<BootError>` view. Install a global JS error handler as the last-resort net. Then run the diagnostic playbook against a fresh APK to confirm which hypothesis actually fired.
+
+**Tech Stack:** Expo SDK 52, React Native 0.76, TypeScript, EAS Build, expo-secure-store, react-native-libsodium.
+
+**Spec:** `docs/superpowers/specs/2026-05-16-android-whitescreen-rca-design.md`
+
+**Decisions inherited from spec review gate:**
+- EAS Secrets (not `eas.json env`) for `EXPO_PUBLIC_*` values.
+- `newArchEnabled: false` is acceptable as a temporary rollback if H2 confirms.
+
+---
+
+## File Overview
+
+**New files (mobile app):**
+- `apps/mobile/components/BootError.tsx` — full-screen error fallback with env diagnostic
+- `apps/mobile/components/BootSplash.tsx` — minimal splash shown while the crypto backend warms up
+- `apps/mobile/components/AppBootstrap.tsx` — boundary that initialises the crypto backend in a `useEffect` and routes errors to `BootError`
+- `apps/mobile/lib/env.test.ts` — lazy proxy + missing-var coverage
+- `apps/mobile/scripts/check-env.mjs` — optional lint comparing `.env.example` against `.env.local`
+
+**Modified files (mobile app):**
+- `apps/mobile/lib/env.ts` — convert to lazy proxy
+- `apps/mobile/app/_layout.tsx` — remove the module-eval crypto init; mount `<AppBootstrap>` at the top of the tree
+- `apps/mobile/README.md` — add an "EAS env" section
+- `apps/mobile/package.json` — add `check:env` script
+
+**No files deleted.** No native code changes.
+
+---
+
+## Phase 0 — Wire env into EAS builds (the leading hypothesis fix)
+
+### Task 1: Create EAS Secrets and document the contract
+
+**Files:**
+- Modify: `apps/mobile/README.md`
+
+- [ ] **Step 1: Confirm EAS CLI is installed and authenticated**
+
+Run:
+
+```bash
+cd apps/mobile
+npx eas-cli --version
+npx eas-cli whoami
+```
+
+Expected: a version string ≥ 13.0.0, and the `whoami` output shows the `bygalax` owner (matches `app.json` `expo.owner`). If `whoami` errors, run `npx eas-cli login` interactively in a terminal (this plan cannot be executed in a sandboxed shell).
+
+- [ ] **Step 2: Create the three project-scoped secrets**
+
+Run, substituting the real Supabase project URL and `sb_publishable_…` anon key (look them up in `apps/mobile/.env.local`):
+
+```bash
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_URL --value '<project-supabase-url>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_ANON_KEY --value '<sb_publishable_key>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_AUTH_REDIRECT_URL --value 'netralax://auth/callback'
+```
+
+Expected: each command prints `✔ Created a new secret EXPO_PUBLIC_…`. List to confirm:
+
+```bash
+npx eas-cli secret:list
+```
+
+Expected: all three names present, type `STRING`, scope `PROJECT`.
+
+- [ ] **Step 3: Document the env contract in README**
+
+Append to `apps/mobile/README.md`:
+
+````markdown
+## EAS Builds and Environment Variables
+
+Production and preview builds load `EXPO_PUBLIC_*` from EAS Secrets — `.env.local` is only honoured by `expo start` locally.
+
+Required secrets (create once per project):
+
+```bash
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_URL --value '<project-supabase-url>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_SUPABASE_ANON_KEY --value '<sb_publishable_key>'
+npx eas-cli secret:create --scope project --name EXPO_PUBLIC_AUTH_REDIRECT_URL --value 'netralax://auth/callback'
+```
+
+Check with `npx eas-cli secret:list`. Missing values cause `env.ts` to throw at the first read, which the `<BootError>` view renders.
+````
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add apps/mobile/README.md
+git commit -m "docs(mobile): document EAS Secrets contract for EXPO_PUBLIC_*"
+```
+
+---
+
+## Phase 1 — Lazy env proxy (TDD)
+
+### Task 2: Failing test for missing env var
+
+**Files:**
+- Create: `apps/mobile/lib/env.test.ts`
+
+- [ ] **Step 1: Write the failing test**
+
+Create `apps/mobile/lib/env.test.ts`:
+
+```ts
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+describe('mobile env (lazy proxy)', () => {
+  beforeEach(() => {
+    vi.resetModules();
+    delete process.env.EXPO_PUBLIC_SUPABASE_URL;
+    delete process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY;
+    delete process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL;
+  });
+
+  it('importing the module does NOT throw when required vars are missing', async () => {
+    await expect(import('./env')).resolves.toBeTruthy();
+  });
+
+  it('reading a property with no env set throws a clear error', async () => {
+    const mod = await import('./env');
+    expect(() => mod.env.supabaseUrl).toThrowError(
+      /Missing required env var EXPO_PUBLIC_SUPABASE_URL/,
+    );
+  });
+
+  it('reading a property after setting env returns the value and memoises', async () => {
+    process.env.EXPO_PUBLIC_SUPABASE_URL = 'https://example.supabase.co';
+    process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY = 'anon-123';
+    const mod = await import('./env');
+    expect(mod.env.supabaseUrl).toBe('https://example.supabase.co');
+    expect(mod.env.supabaseAnonKey).toBe('anon-123');
+    expect(mod.env.authRedirectUrl).toBe('netralax://auth/callback');
+  });
+});
+```
+
+- [ ] **Step 2: Run test, confirm it fails for the right reason**
+
+Run:
+
+```bash
+pnpm --filter @chat-app/mobile test -- env.test
+```
+
+Expected: `importing the module does NOT throw when required vars are missing` FAILS because the current `env.ts` evaluates `required(...)` at module-eval time. This proves the test is wired correctly. Do NOT proceed if a different test fails first — fix the wiring before editing source.
+
+### Task 3: Convert `env.ts` to a lazy proxy
+
+**Files:**
+- Modify: `apps/mobile/lib/env.ts`
+
+- [ ] **Step 1: Replace the module body with the lazy proxy**
+
+Overwrite `apps/mobile/lib/env.ts` with:
+
+```ts
+// EXPO_PUBLIC_* vars are inlined at bundle time by Expo's Babel plugin (or
+// shipped via EAS Secrets for EAS builds — see apps/mobile/README.md).
+// We pull them through a Proxy so missing vars throw on first READ, not at
+// module-eval time. That keeps the throw inside the React tree where the
+// <BootError> boundary can render it as a readable screen instead of a blank
+// white window.
+
+function required(name: string): string {
+  const v = process.env[name];
+  if (!v || v.length === 0) {
+    throw new Error(
+      'Missing required env var ' + name +
+        '. Set it via `eas secret:create --scope project --name ' + name +
+        ' --value ...` or in apps/mobile/.env.local for local dev (see .env.example).',
+    );
+  }
+  return v;
+}
+
+interface EnvShape {
+  supabaseUrl: string;
+  supabaseAnonKey: string;
+  authRedirectUrl: string;
+}
+
+function readEnv(): EnvShape {
+  return {
+    supabaseUrl: required('EXPO_PUBLIC_SUPABASE_URL'),
+    supabaseAnonKey: required('EXPO_PUBLIC_SUPABASE_ANON_KEY'),
+    authRedirectUrl: process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL ?? 'netralax://auth/callback',
+  };
+}
+
+let cached: EnvShape | null = null;
+
+export const env: EnvShape = new Proxy({} as EnvShape, {
+  get(_target, key: string | symbol): unknown {
+    cached ??= readEnv();
+    return cached[key as keyof EnvShape];
+  },
+});
+```
+
+- [ ] **Step 2: Re-run the env tests**
+
+```bash
+pnpm --filter @chat-app/mobile test -- env.test
+```
+
+Expected: all three tests PASS.
+
+- [ ] **Step 3: Run the full mobile test suite**
+
+```bash
+pnpm --filter @chat-app/mobile test
+```
+
+Expected: no regressions. If a test depended on the old eager-throw behaviour, update it inline to expect a lazy throw.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add apps/mobile/lib/env.ts apps/mobile/lib/env.test.ts
+git commit -m "fix(mobile): lazy env proxy so missing EXPO_PUBLIC vars throw inside React"
+```
+
+---
+
+## Phase 2 — Bootstrap boundary + global handler
+
+### Task 4: Create `BootSplash` and `BootError`
+
+**Files:**
+- Create: `apps/mobile/components/BootSplash.tsx`
+- Create: `apps/mobile/components/BootError.tsx`
+
+- [ ] **Step 1: Create the splash**
+
+`apps/mobile/components/BootSplash.tsx`:
+
+```tsx
+import { ActivityIndicator, StyleSheet, View } from 'react-native';
+
+import { colors } from '../theme/colors';
+
+// Shown while AppBootstrap is initialising the crypto backend. Identical
+// background to the Expo splash so the handoff is invisible to the user.
+export function BootSplash() {
+  return (
+    <View style={styles.container}>
+      <ActivityIndicator color={colors.accent} />
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    alignItems: 'center',
+    justifyContent: 'center',
+    backgroundColor: colors.bg,
+  },
+});
+```
+
+- [ ] **Step 2: Create the error view**
+
+`apps/mobile/components/BootError.tsx`:
+
+```tsx
+import { ScrollView, StyleSheet, Text, View } from 'react-native';
+
+import { colors } from '../theme/colors';
+
+interface Props {
+  error: Error;
+}
+
+// Last-resort fallback. Renders whenever AppBootstrap's init effect throws or
+// when the global JS error handler catches an unhandled exception. The
+// env-diagnostic line ("env-ok" / "env-missing") makes future bug reports
+// triageable from a single screenshot.
+export function BootError({ error }: Props) {
+  const envOk = Boolean(process.env.EXPO_PUBLIC_SUPABASE_URL);
+  return (
+    <ScrollView contentContainerStyle={styles.container}>
+      <Text style={styles.title}>App-Start fehlgeschlagen</Text>
+      <Text style={styles.message}>{error.message}</Text>
+      <View style={styles.diagnostic}>
+        <Text style={styles.diagnosticLabel}>EXPO_PUBLIC_SUPABASE_URL:</Text>
+        <Text style={[styles.diagnosticValue, envOk ? styles.ok : styles.bad]}>
+          {envOk ? 'env-ok' : 'env-missing'}
+        </Text>
+      </View>
+      {error.stack && <Text style={styles.stack}>{error.stack}</Text>}
+    </ScrollView>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flexGrow: 1,
+    backgroundColor: colors.bg,
+    padding: 24,
+    paddingTop: 64,
+    gap: 12,
+  },
+  title: { color: colors.text, fontSize: 20, fontWeight: '700' },
+  message: { color: colors.danger, fontSize: 14, lineHeight: 20 },
+  diagnostic: { flexDirection: 'row', gap: 8, marginTop: 8 },
+  diagnosticLabel: { color: colors.textMuted, fontSize: 12 },
+  diagnosticValue: { fontSize: 12, fontWeight: '700' },
+  ok: { color: colors.success },
+  bad: { color: colors.danger },
+  stack: {
+    color: colors.textDim,
+    fontSize: 11,
+    fontFamily: 'Courier',
+    marginTop: 16,
+  },
+});
+```
+
+- [ ] **Step 3: Commit (no test yet — these are render-only components)**
+
+```bash
+git add apps/mobile/components/BootSplash.tsx apps/mobile/components/BootError.tsx
+git commit -m "feat(mobile): BootSplash + BootError fallback views for AppBootstrap"
+```
+
+### Task 5: Create `AppBootstrap` boundary
+
+**Files:**
+- Create: `apps/mobile/components/AppBootstrap.tsx`
+
+- [ ] **Step 1: Write the boundary**
+
+`apps/mobile/components/AppBootstrap.tsx`:
+
+```tsx
+import { crypto } from '@chat-app/shared';
+import { type ReactNode, useEffect, useState } from 'react';
+
+import { createLibsodiumBackend } from '../lib/cryptoBackend';
+import { BootError } from './BootError';
+import { BootSplash } from './BootSplash';
+
+interface Props {
+  children: ReactNode;
+}
+
+// React Native exposes ErrorUtils on the global. The types ship with RN but
+// we cast defensively because the renderer used by Vitest does not.
+interface RNErrorUtils {
+  getGlobalHandler: () => (err: Error, isFatal?: boolean) => void;
+  setGlobalHandler: (handler: (err: Error, isFatal?: boolean) => void) => void;
+}
+
+// Initialises the crypto backend inside a useEffect (not at module-eval) so
+// any failure surfaces in the React tree. Also installs a global JS error
+// handler that routes unhandled throws to BootError; this catches errors
+// thrown during render (e.g. the lazy env proxy reading a missing var) that
+// would otherwise escape every per-screen ErrorBoundary.
+export function AppBootstrap({ children }: Props) {
+  const [error, setError] = useState<Error | null>(null);
+  const [ready, setReady] = useState(false);
+
+  useEffect(() => {
+    try {
+      crypto.setCryptoBackend(createLibsodiumBackend());
+      setReady(true);
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e : new Error(String(e)));
+    }
+  }, []);
+
+  useEffect(() => {
+    const eu = (globalThis as unknown as { ErrorUtils?: RNErrorUtils }).ErrorUtils;
+    if (!eu) return;
+    const prev = eu.getGlobalHandler();
+    eu.setGlobalHandler((err, isFatal) => {
+      prev?.(err, isFatal);
+      setError(err);
+    });
+    return () => eu.setGlobalHandler(prev);
+  }, []);
+
+  if (error) return <BootError error={error} />;
+  if (!ready) return <BootSplash />;
+  return <>{children}</>;
+}
+```
+
+- [ ] **Step 2: Typecheck**
+
+```bash
+pnpm --filter @chat-app/mobile typecheck
+```
+
+Expected: no new errors.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add apps/mobile/components/AppBootstrap.tsx
+git commit -m "feat(mobile): AppBootstrap boundary — defers crypto init, catches global throws"
+```
+
+### Task 6: Rewire `_layout.tsx`
+
+**Files:**
+- Modify: `apps/mobile/app/_layout.tsx`
+
+- [ ] **Step 1: Replace the module-eval crypto init with `<AppBootstrap>`**
+
+Overwrite `apps/mobile/app/_layout.tsx` with:
+
+```tsx
+import { Stack } from 'expo-router';
+import { StatusBar } from 'expo-status-bar';
+import { GestureHandlerRootView } from 'react-native-gesture-handler';
+import { SafeAreaProvider } from 'react-native-safe-area-context';
+
+import { AppBootstrap } from '../components/AppBootstrap';
+import { ErrorBoundary } from '../components/ErrorBoundary';
+import { IncomingCallModal } from '../components/IncomingCallModal';
+import { AuthProvider } from '../lib/authContext';
+import { CallProvider } from '../lib/callContext';
+
+export default function RootLayout() {
+  return (
+    <GestureHandlerRootView style={{ flex: 1 }}>
+      <SafeAreaProvider>
+        <AppBootstrap>
+          <ErrorBoundary>
+            <AuthProvider>
+              <CallProvider>
+                <StatusBar style="auto" />
+                <Stack screenOptions={{ headerShown: false }}>
+                  <Stack.Screen name="index" />
+                  <Stack.Screen name="(app)" />
+                  <Stack.Screen name="auth/callback" />
+                </Stack>
+                <IncomingCallModal />
+              </CallProvider>
+            </AuthProvider>
+          </ErrorBoundary>
+        </AppBootstrap>
+      </SafeAreaProvider>
+    </GestureHandlerRootView>
+  );
+}
+```
+
+Two structural changes vs. the prior version:
+
+1. Removed the top-level `crypto.setCryptoBackend(createLibsodiumBackend())` call — it now runs inside `AppBootstrap`'s `useEffect`.
+2. `<AppBootstrap>` sits OUTSIDE `<ErrorBoundary>` so a boot failure renders `<BootError>` instead of trying (and failing) to hit `ErrorBoundary`'s consumer-tree path.
+
+- [ ] **Step 2: Typecheck**
+
+```bash
+pnpm --filter @chat-app/mobile typecheck
+```
+
+Expected: no errors. The previously-direct `crypto` + `createLibsodiumBackend` imports are now gone from `_layout.tsx`; if either is reported as unused, remove the stale import.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add apps/mobile/app/_layout.tsx
+git commit -m "fix(mobile): defer crypto backend init into AppBootstrap (prevents white-screen)"
+```
+
+---
+
+## Phase 3 — Local validation (sanity before remote build)
+
+### Task 7: Local smoke (Expo Go / dev client) — env-missing path
+
+**Files:**
+- None (local sanity, no edits)
+
+- [ ] **Step 1: Temporarily clear local env**
+
+```bash
+mv apps/mobile/.env.local apps/mobile/.env.local.bak
+```
+
+- [ ] **Step 2: Start the dev server**
+
+```bash
+pnpm --filter @chat-app/mobile dev
+```
+
+In a connected Android emulator / device, open the dev client.
+
+Expected: app reaches `<BootError>` with the message `Missing required env var EXPO_PUBLIC_SUPABASE_URL ...` and the diagnostic line `EXPO_PUBLIC_SUPABASE_URL: env-missing`. **No white screen.**
+
+- [ ] **Step 3: Restore env**
+
+```bash
+mv apps/mobile/.env.local.bak apps/mobile/.env.local
+```
+
+Reload the dev client.
+
+Expected: app boots normally to the login screen.
+
+- [ ] **Step 4: No commit (validation only)**
+
+No-op.
+
+---
+
+## Phase 4 — Remote build validation (the actual RCA)
+
+### Task 8: Run the diagnostic playbook against a real APK
+
+**Files:**
+- None (investigative; outcome determines whether Phase 5 fixes are needed)
+
+- [ ] **Step 1: Build the preview APK with EAS Secrets present**
+
+```bash
+cd apps/mobile
+npx eas-cli build --profile preview --platform android
+```
+
+Expected: build succeeds. Note the APK URL.
+
+- [ ] **Step 2: Install on a connected Android device**
+
+```bash
+adb install -r <downloaded-apk>.apk
+```
+
+Expected: install succeeds.
+
+- [ ] **Step 3: Capture logs while launching**
+
+```bash
+adb logcat -c
+adb logcat *:E ReactNative:V ReactNativeJS:V &
+# tap the launcher icon for the app
+```
+
+Triage the first 50 lines for the first `Error`, `Exception`, or `FATAL` after the app starts.
+
+- [ ] **Step 4: Match the trace against a hypothesis**
+
+| Trace pattern | Hypothesis | Next action |
+|---|---|---|
+| `Missing required env var EXPO_PUBLIC_…` rendered to BootError (no red box) | H1 — fix already applied | Skip to Phase 6 |
+| `Native module … not found` / `RNLibsodium not found` | H3 — libsodium native autolink missing | Phase 5 Task 9 |
+| `JNI DETECTED ERROR` / `Fatal signal 11 (SIGSEGV)` before any RN log | H2 — new arch + incompatible lib | Phase 5 Task 10 |
+| `libsodium-wrappers-sumo` or `WebAssembly` in the trace | H4 — covered by the mobile-encryption-port plan | Note the trace; merge that plan next |
+| App reaches login screen | H1 was the root cause; nothing more to do | Skip to Phase 6 |
+
+- [ ] **Step 5: Write a one-paragraph note in the PR description**
+
+Capture which hypothesis confirmed, log lines, and which Phase 5 task (if any) was needed. This becomes the regression record.
+
+---
+
+## Phase 5 — Hypothesis-specific fixes (conditional)
+
+Only run the tasks that the Step 4 triage selected. If H1 alone resolves it, skip Phase 5 entirely.
+
+### Task 9 (conditional, H3): Force re-link `react-native-libsodium`
+
+**Files:**
+- Modify: `apps/mobile/app.json` (only if `expo prebuild` adds a plugin entry — see below)
+
+- [ ] **Step 1: Run `expo prebuild` to regenerate native projects**
+
+```bash
+cd apps/mobile
+npx expo prebuild --clean --platform android
+```
+
+Expected: an `android/` directory is created (or refreshed), and `app.json` may gain a `plugins` entry for `react-native-libsodium` if the lib ships a config plugin.
+
+- [ ] **Step 2: Rebuild and re-test**
+
+```bash
+npx eas-cli build --profile preview --platform android
+```
+
+Install, repeat Phase 4 Step 3-4.
+
+Expected: native module is now found. If still missing, escalate to the lib's GitHub issues — it likely needs a manual Gradle entry in `android/app/build.gradle`.
+
+- [ ] **Step 3: Commit any generated config**
+
+If `app.json` changed, commit the diff:
+
+```bash
+git add apps/mobile/app.json
+git commit -m "fix(mobile): re-link react-native-libsodium via expo prebuild"
+```
+
+If `android/` is ignored (Expo managed flow), document the prebuild step in the README under the "EAS env" section instead.
+
+### Task 10 (conditional, H2): Temporarily disable `newArchEnabled`
+
+**Files:**
+- Modify: `apps/mobile/app.json`
+
+- [ ] **Step 1: Toggle the flag**
+
+Edit `apps/mobile/app.json`, change `"newArchEnabled": true` → `"newArchEnabled": false`. Note in the commit message which library is suspected and the upstream issue link.
+
+- [ ] **Step 2: Rebuild and re-test**
+
+```bash
+npx eas-cli build --profile preview --platform android
+```
+
+Install, repeat Phase 4 Step 3-4.
+
+Expected: app boots to login.
+
+- [ ] **Step 3: Open a follow-up issue**
+
+Create a tracking issue in the repo titled `mobile: re-enable newArchEnabled once <lib> is Fabric-ready` with the trace from Phase 4 attached. Link to the affected lib's tracker.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add apps/mobile/app.json
+git commit -m "fix(mobile): temporarily disable newArchEnabled (white-screen on Android)
+
+Suspected incompatibility: <library@version>. Tracked in #<issue>."
+```
+
+---
+
+## Phase 6 — Optional hardening
+
+### Task 11: `check:env` lint script
+
+**Files:**
+- Create: `apps/mobile/scripts/check-env.mjs`
+- Modify: `apps/mobile/package.json`
+
+- [ ] **Step 1: Add the script**
+
+`apps/mobile/scripts/check-env.mjs`:
+
+```js
+#!/usr/bin/env node
+// Compares apps/mobile/.env.example with .env.local. Surfaces missing keys
+// so an onboarding dev doesn't ship a build that white-screens.
+
+import { existsSync, readFileSync } from 'node:fs';
+import { dirname, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const here = dirname(fileURLToPath(import.meta.url));
+const mobileRoot = resolve(here, '..');
+const examplePath = resolve(mobileRoot, '.env.example');
+const localPath = resolve(mobileRoot, '.env.local');
+
+if (!existsSync(localPath)) {
+  console.error('No .env.local found at ' + localPath);
+  console.error('Copy .env.example to .env.local and fill in values.');
+  process.exit(1);
+}
+
+function keysOf(path) {
+  return new Set(
+    readFileSync(path, 'utf8')
+      .split('\n')
+      .map((line) => line.trim())
+      .filter((line) => line.length > 0 && !line.startsWith('#'))
+      .map((line) => line.split('=', 1)[0]),
+  );
+}
+
+const exampleKeys = keysOf(examplePath);
+const localKeys = keysOf(localPath);
+const missing = [...exampleKeys].filter((k) => !localKeys.has(k));
+
+if (missing.length > 0) {
+  console.error('Missing keys in .env.local: ' + missing.join(', '));
+  process.exit(1);
+}
+console.log('env-ok: all .env.example keys present in .env.local');
+```
+
+- [ ] **Step 2: Wire the script into `package.json`**
+
+In `apps/mobile/package.json`, under `scripts`, add:
+
+```json
+"check:env": "node scripts/check-env.mjs"
+```
+
+- [ ] **Step 3: Smoke**
+
+```bash
+pnpm --filter @chat-app/mobile run check:env
+```
+
+Expected: `env-ok: all .env.example keys present in .env.local`.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add apps/mobile/scripts/check-env.mjs apps/mobile/package.json
+git commit -m "chore(mobile): check:env script lints .env.local against .env.example"
+```
+
+---
+
+## Phase 7 — Wrap-up
+
+### Task 12: PR + post-mortem note
+
+- [ ] **Step 1: Push branch + open PR**
+
+```bash
+git push -u origin <branch-name>
+gh pr create --title "fix(mobile): Android white-screen RCA + defense-in-depth" --body "..."
+```
+
+PR body must contain:
+
+```
+## Summary
+
+- Lazy env proxy so missing EXPO_PUBLIC_* throws inside React.
+- AppBootstrap boundary mounts before AuthProvider; renders BootError on init failure.
+- Global ErrorUtils handler routes unhandled throws to BootError.
+- EAS Secrets documented in README; eas.json untouched.
+
+## RCA outcome
+
+<paste Phase 4 Step 5 paragraph>
+
+## Test plan
+
+- [x] Local: env-cleared dev client shows BootError, not white screen.
+- [x] Remote: preview APK installed on Android device; <result>.
+- [x] check:env script passes.
+- [x] All mobile unit tests green.
+```
+
+- [ ] **Step 2: Mark plan complete**
+
+This plan is done when the Android preview build opens to the login screen and `<BootError>` renders correctly with env intentionally cleared.
+
+---
+
+## Spec coverage check
+
+- Hypothesis H1 — EAS Secrets (Task 1), lazy env (Task 3), env test (Task 2). ✅
+- Hypothesis H2 — Diagnostic (Task 8), conditional Task 10 fix. ✅
+- Hypothesis H3 — Diagnostic (Task 8), conditional Task 9 fix. ✅
+- Hypothesis H4 — Diagnostic only (Task 8); structural fix belongs to the mobile-encryption-port plan. ✅
+- Hypothesis H5 — Documented in Task 8 Step 4 table; cost of an asset eyeball is zero, no separate task needed. ✅
+- Defense-in-depth 1 (lazy env) — Tasks 2-3. ✅
+- Defense-in-depth 2 (AppBootstrap) — Tasks 4-6. ✅
+- Defense-in-depth 3 (global handler) — Task 5. ✅
+- Defense-in-depth 4 (SecureStore probe) — deferred (see Out of Scope). ✅
+- Defense-in-depth 5 (`check:env`) — Task 11. ✅
+
+## Out of scope for this plan (in spec, but deferred)
+
+- SecureStore availability probe — only relevant on rare Android factory-test profiles. Add later if Phase 4 surfaces a SecureStore symptom.
+- Sentry / Bugsnag integration — spec lists this under future work.