chore(desktop): release v0.21.4

Friend-DM "Nachricht nicht lesbar" recurred even after v0.21.3 because the
proactive sweep called shareConvKeyToUser, which reads the module-level
conv-key cache first. After a server-side cleanup the cache still held the
stale locally-bootstrapped key, so each side wrapped its own different key
for the peer and the bundles diverged anew.

Switch the sweep to rotate_conv_key when any peer's user-id bundle is
missing at the active version: a fresh symmetric key is generated, wrapped
for every member at their CURRENT pubkey, and the active version is bumped
under a row-level FOR UPDATE lock. Concurrent rotations are race-safe — the
loser sees "new version must be greater" and bails; the winner's bundles
propagate via realtime.

Realtime conversation_keys subscription now invalidates the cache for the
affected (conversationId, key_version) on any INSERT/UPDATE/DELETE — so
admin cleanups, peer rotations, or device wraps can no longer leave a
stale entry in this client's session cache.

queueInsert now fires the first event of a quiet period immediately and
only collapses follow-up bursts. BATCH_WINDOW_MS dropped 250 → 80 ms.
This closes the ~250 ms gap between the notification sound and the
message body appearing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop/electron/ipc-types.ts

@@ -107,6 +107,11 @@ export const CHANNELS = {
   // OS fullscreen so the Windows taskbar / macOS menubar gets covered.
   WINDOW_SET_FULLSCREEN: 'window:set-fullscreen',
 
+  // Content-protection toggle. Enables/disables OS-level screenshot/screen-
+  // recording block (WDA_MONITOR on Windows, NSWindowSharingNone on macOS)
+  // while a view-once image is being revealed. No-op on Linux X11.
+  WINDOW_SET_CONTENT_PROTECTION: 'window:set-content-protection',
+
   // 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
@@ -271,6 +276,12 @@ export interface UpdateProgress {
   total: number;
 }
 
+// ---- Window content protection -------------------------------------------
+
+export interface WindowSetContentProtectionArgs {
+  enabled: boolean;
+}
+
 // ---- Runtime marker ------------------------------------------------------
 
 /** Value exposed on `window.electronAPI.platform`. Used by the renderer

apps/desktop/electron/main.ts

@@ -26,6 +26,7 @@ import { register as registerShortcuts } from './modules/shortcuts';
 import { register as registerSql } from './modules/sql';
 import { register as registerTray } from './modules/tray';
 import { register as registerUpdater } from './modules/updater';
+import { register as registerWindowContentProtection } from './modules/window-content-protection';
 import { register as registerWindowFullscreen } from './modules/window-fullscreen';
 import { attach as attachWindowState, loadState } from './window-state';
 
@@ -274,6 +275,7 @@ if (!gotLock) {
     registerTray(mainWindow);
     registerUpdater(mainWindow);
     registerWindowFullscreen(mainWindow);
+    registerWindowContentProtection(mainWindow);
     registerAudioLoopback(mainWindow);
   });
 

apps/desktop/electron/modules/window-content-protection.ts

@@ -0,0 +1,36 @@
+// Window content-protection adapter. Enables / disables OS-level
+// screenshot and screen-recording blocking on the host BrowserWindow.
+//
+//   Windows: WDA_MONITOR (SetWindowDisplayAffinity) — the window surface
+//            appears black in any screen capture tool (OBS, Snipping Tool,
+//            Win+PrtScr, etc.) while protection is enabled.
+//   macOS:   NSWindowSharingNone — equivalent coverage for QuickTime,
+//            Cmd+Shift+3/4, and external recorders.
+//   Linux:   No-op. Electron exposes the API on all platforms but the
+//            X11/Wayland compositors don't honour it in Electron 33.
+//
+// Called by the renderer during view-once image reveals so the image
+// cannot be captured by an OS-level screenshot while it is on screen.
+
+import { BrowserWindow, ipcMain } from 'electron';
+
+import { CHANNELS, type WindowSetContentProtectionArgs } from '../ipc-types';
+
+export function register(mainWindow: BrowserWindow): void {
+  ipcMain.handle(
+    CHANNELS.WINDOW_SET_CONTENT_PROTECTION,
+    (_evt, args: WindowSetContentProtectionArgs) => {
+      // Electron's setContentProtection covers Windows (WDA_MONITOR) and
+      // macOS (NSWindowSharingNone) in one call. No-op on Linux X11.
+      // Wrapped in try/catch because the window can already be destroyed
+      // by the time this fires during a teardown.
+      try {
+        const win = BrowserWindow.fromWebContents(_evt.sender) ?? mainWindow;
+        if (!win || win.isDestroyed()) return;
+        win.setContentProtection(args.enabled);
+      } catch (err) {
+        console.warn('setContentProtection failed', err);
+      }
+    },
+  );
+}

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

@@ -96,6 +96,12 @@ export interface ElectronAPI {
 
   setFullscreen: (enabled: boolean) => Promise<void>;
 
+  /** Block OS-level screen capture (Win+PrtScr, OBS, etc.) while a
+   *  view-once image is being revealed. Covers Windows (WDA_MONITOR) and
+   *  macOS (NSWindowSharingNone). No-op on Linux X11. Optional: always
+   *  feature-check because the web build has no preload bridge. */
+  setContentProtection?: (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;

apps/desktop/electron/preload.ts

@@ -160,6 +160,10 @@ const api = {
   setFullscreen: (enabled: boolean): Promise<void> =>
     ipcRenderer.invoke(CHANNELS.WINDOW_SET_FULLSCREEN, enabled),
 
+  // Window content protection ----------------------------------------------
+  setContentProtection: (enabled: boolean): Promise<void> =>
+    ipcRenderer.invoke(CHANNELS.WINDOW_SET_CONTENT_PROTECTION, { enabled }),
+
   // OS hostname ------------------------------------------------------------
   getHostname: (): Promise<string | null> => ipcRenderer.invoke(CHANNELS.APP_HOSTNAME),
 

apps/desktop/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@chat-app/desktop",
-  "version": "0.20.0",
+  "version": "0.21.4",
   "private": true,
   "description": "Electron desktop client (Windows / macOS / Linux)",
   "type": "module",

apps/desktop/src/App.tsx

@@ -1,5 +1,5 @@
-import { lazy, Suspense } from 'react';
+import { lazy, Suspense, useEffect } from 'react';
-import { HashRouter, Navigate, Outlet, Route, Routes } from 'react-router-dom';
+import { HashRouter, Navigate, Outlet, Route, Routes, useParams } from 'react-router-dom';
 
 import { AppShell } from './components/AppShell';
 import { CrashToast } from './components/CrashToast';
@@ -13,6 +13,7 @@ import { CallProvider } from './context/CallContext';
 import { ConversationsProvider } from './context/ConversationsContext';
 import { FriendshipsProvider } from './context/FriendshipsContext';
 import { ThemeProvider } from './context/ThemeContext';
+import { hydrateDrafts } from './lib/composerDraftStore';
 import { AuthPage } from './pages/AuthPage';
 import { ChatsEmptyState, ChatsPage } from './pages/ChatsPage';
 import { ConversationPage } from './pages/ConversationPage';
@@ -60,7 +61,23 @@ function RouteBoundary({ scope }: { scope: string }) {
   );
 }
 
+// Forces a fresh `ConversationPage` instance per `:id` so React unmounts
+// the previous conversation entirely on switch. Without this, the same
+// component instance handles every conversation, which leaks state
+// between chats (messages, scroll position, composer drafts) for one
+// render frame and gives the "flicker" we're trying to remove.
+// `useConversationMessages` re-hydrates from `messageMemoryCache` on the
+// fresh mount so previously-visited chats still render instantly.
+function ConversationRoute() {
+  const { id } = useParams<{ id: string }>();
+  return <ConversationPage key={id ?? '__no_id__'} />;
+}
+
 export function App() {
+  useEffect(() => {
+    void hydrateDrafts();
+  }, []);
+
   return (
     <ErrorBoundary scope="root">
       <ThemeProvider>
@@ -114,7 +131,7 @@ export function App() {
                                 path=":id"
                                 element={
                                   <ErrorBoundary scope="conversation">
-                                    <ConversationPage />
+                                    <ConversationRoute />
                                   </ErrorBoundary>
                                 }
                               />

apps/desktop/src/components/AttachmentAudio.tsx

@@ -2,6 +2,7 @@ import { type AttachmentHandle, downloadAndDecryptAttachment } from '@chat-app/s
 import { useEffect, useMemo, useRef, useState } from 'react';
 
 import { getCachedAttachment, putCachedAttachment } from '../lib/attachmentCache';
+import { getVoiceSpeed, setVoiceSpeed, VOICE_SPEEDS, type VoiceSpeed } from '../lib/voiceSpeedSettings';
 import { supabase } from '../lib/supabase';
 import { AlertIcon, MicIcon, SpinnerIcon } from './icons';
 
@@ -23,6 +24,7 @@ export function AttachmentAudio({ handle }: Props) {
   const [duration, setDuration] = useState<number>(0);
   const [position, setPosition] = useState<number>(0);
   const [playing, setPlaying] = useState(false);
+  const [speed, setSpeed] = useState<VoiceSpeed>(() => getVoiceSpeed());
   const audioRef = useRef<HTMLAudioElement | null>(null);
 
   useEffect(() => {
@@ -105,6 +107,12 @@ export function AttachmentAudio({ handle }: Props) {
     };
   }, [arrayBuf]);
 
+  useEffect(() => {
+    const el = audioRef.current;
+    if (!el) return;
+    el.playbackRate = speed;
+  }, [speed, blobUrl]);
+
   const fallbackPeaks = useMemo(
     () => (peaks ? null : Array.from({ length: BAR_COUNT }, () => 0.5)),
     [peaks],
@@ -154,6 +162,29 @@ export function AttachmentAudio({ handle }: Props) {
           <PlayGlyph />
         )}
       </button>
+      <div className="flex shrink-0 items-center gap-0.5 rounded-md bg-surface-3 p-0.5 text-[10px] font-semibold text-fg-muted">
+        {VOICE_SPEEDS.map((s) => {
+          const active = s === speed;
+          return (
+            <button
+              key={s}
+              type="button"
+              onClick={() => {
+                setSpeed(s);
+                setVoiceSpeed(s);
+              }}
+              className={
+                'flex h-6 w-7 cursor-pointer items-center justify-center rounded transition ' +
+                (active ? 'bg-accent text-accent-fg' : 'hover:bg-surface hover:text-fg')
+              }
+              aria-pressed={active}
+              title={'Wiedergabegeschwindigkeit ' + s + '×'}
+            >
+              {s}×
+            </button>
+          );
+        })}
+      </div>
       <div className="flex min-w-0 flex-1 flex-col gap-1">
         <div
           role="slider"

apps/desktop/src/components/ScreenShareAnnotations.tsx

@@ -0,0 +1,220 @@
+import { useCallback, useEffect, useRef, useState } from 'react';
+
+import { useAuth } from '../context/AuthContext';
+import { supabase } from '../lib/supabase';
+import { PencilIcon, XIcon } from './icons';
+
+interface Stroke {
+  id: string;
+  userId: string;
+  color: string;
+  // normalized 0..1 coordinates so any viewer's canvas size renders consistently
+  points: Array<[number, number]>;
+  bornAt: number;
+}
+
+interface Props {
+  /** Stable per-share key. Use the share's participantId. */
+  shareKey: string;
+  /** Render annotations transparently (off when the toolbar is closed). */
+  enabled: boolean;
+  onToggleEnabled: (next: boolean) => void;
+}
+
+const FADE_MS = 8000;
+const COLORS = ['#ef4444', '#3b82f6', '#22c55e', '#facc15', '#a855f7', '#000000'] as const;
+
+export function ScreenShareAnnotations({ shareKey, enabled, onToggleEnabled }: Props) {
+  const { session } = useAuth();
+  const userId = session?.user.id ?? 'anon';
+  const [color, setColor] = useState<string>(COLORS[0]);
+  const [strokes, setStrokes] = useState<Stroke[]>([]);
+  const draftRef = useRef<Stroke | null>(null);
+  const containerRef = useRef<HTMLDivElement | null>(null);
+  const canvasRef = useRef<HTMLCanvasElement | null>(null);
+
+  const broadcastRef = useRef<((s: Stroke) => void) | null>(null);
+
+  // Subscribe to remote strokes.
+  useEffect(() => {
+    const channel = supabase.channel('screen-annotation:' + shareKey, {
+      config: { broadcast: { self: false } },
+    });
+    channel.on('broadcast', { event: 'stroke' }, (payload) => {
+      const s = payload.payload as Stroke | undefined;
+      if (!s || s.userId === userId) return;
+      setStrokes((prev) => [...prev, { ...s, bornAt: Date.now() }]);
+    });
+    channel.subscribe();
+    broadcastRef.current = (s: Stroke) => {
+      void channel.send({
+        type: 'broadcast',
+        event: 'stroke',
+        payload: s,
+      });
+    };
+    return () => {
+      broadcastRef.current = null;
+      void supabase.removeChannel(channel);
+    };
+  }, [shareKey, userId]);
+
+  // Garbage-collect faded strokes after FADE_MS + a small grace window.
+  useEffect(() => {
+    if (strokes.length === 0) return;
+    const id = setInterval(() => {
+      const cutoff = Date.now() - FADE_MS - 500;
+      setStrokes((prev) => {
+        const next = prev.filter((s) => s.bornAt > cutoff);
+        return next.length === prev.length ? prev : next;
+      });
+    }, 1000);
+    return () => clearInterval(id);
+  }, [strokes.length]);
+
+  // Paint the canvas on every render tick.
+  useEffect(() => {
+    const cv = canvasRef.current;
+    const container = containerRef.current;
+    if (!cv || !container) return;
+    const rect = container.getBoundingClientRect();
+    if (cv.width !== rect.width || cv.height !== rect.height) {
+      cv.width = Math.max(1, Math.floor(rect.width));
+      cv.height = Math.max(1, Math.floor(rect.height));
+    }
+    const ctx = cv.getContext('2d');
+    if (!ctx) return;
+    ctx.clearRect(0, 0, cv.width, cv.height);
+    const now = Date.now();
+    const drawStroke = (s: Stroke) => {
+      const age = now - s.bornAt;
+      const alpha = Math.max(0, 1 - age / FADE_MS);
+      if (alpha <= 0) return;
+      ctx.save();
+      ctx.globalAlpha = alpha;
+      ctx.strokeStyle = s.color;
+      ctx.lineWidth = 3;
+      ctx.lineCap = 'round';
+      ctx.lineJoin = 'round';
+      ctx.beginPath();
+      for (let i = 0; i < s.points.length; i++) {
+        const [nx, ny] = s.points[i]!;
+        const x = nx * cv.width;
+        const y = ny * cv.height;
+        if (i === 0) ctx.moveTo(x, y);
+        else ctx.lineTo(x, y);
+      }
+      ctx.stroke();
+      ctx.restore();
+    };
+    for (const s of strokes) drawStroke(s);
+    if (draftRef.current) drawStroke(draftRef.current);
+  });
+
+  // Animation frame loop so faded strokes visually decay between paints.
+  useEffect(() => {
+    if (strokes.length === 0 && !draftRef.current) return;
+    let raf = 0;
+    const tick = () => {
+      // Nudge state to force a re-paint. Slightly hacky but cheaper than a
+      // dedicated refresh state.
+      setStrokes((prev) => prev.slice());
+      raf = window.requestAnimationFrame(tick);
+    };
+    raf = window.requestAnimationFrame(tick);
+    return () => window.cancelAnimationFrame(raf);
+  }, [strokes.length]);
+
+  const normalized = useCallback((e: React.PointerEvent<HTMLDivElement>) => {
+    const container = containerRef.current;
+    if (!container) return [0, 0] as [number, number];
+    const rect = container.getBoundingClientRect();
+    const nx = (e.clientX - rect.left) / rect.width;
+    const ny = (e.clientY - rect.top) / rect.height;
+    return [Math.min(1, Math.max(0, nx)), Math.min(1, Math.max(0, ny))] as [number, number];
+  }, []);
+
+  const onPointerDown = (e: React.PointerEvent<HTMLDivElement>) => {
+    if (!enabled) return;
+    (e.currentTarget as HTMLDivElement).setPointerCapture(e.pointerId);
+    draftRef.current = {
+      id: Math.random().toString(36).slice(2),
+      userId,
+      color,
+      points: [normalized(e)],
+      bornAt: Date.now(),
+    };
+  };
+
+  const onPointerMove = (e: React.PointerEvent<HTMLDivElement>) => {
+    if (!draftRef.current) return;
+    draftRef.current.points.push(normalized(e));
+    setStrokes((prev) => prev.slice()); // cheap re-render trigger
+  };
+
+  const onPointerUp = (e: React.PointerEvent<HTMLDivElement>) => {
+    const target = e.currentTarget as HTMLDivElement;
+    if (target.hasPointerCapture(e.pointerId)) target.releasePointerCapture(e.pointerId);
+    const draft = draftRef.current;
+    draftRef.current = null;
+    if (!draft || draft.points.length < 2) {
+      setStrokes((prev) => prev.slice());
+      return;
+    }
+    setStrokes((prev) => [...prev, draft]);
+    broadcastRef.current?.(draft);
+  };
+
+  return (
+    <>
+      <div
+        ref={containerRef}
+        onPointerDown={onPointerDown}
+        onPointerMove={onPointerMove}
+        onPointerUp={onPointerUp}
+        onPointerLeave={onPointerUp}
+        className={
+          'absolute inset-0 z-10 ' +
+          (enabled ? 'cursor-crosshair touch-none' : 'pointer-events-none')
+        }
+      >
+        <canvas
+          ref={canvasRef}
+          className="pointer-events-none absolute inset-0 h-full w-full"
+        />
+      </div>
+      <div className="absolute right-3 top-12 z-20 flex flex-col items-end gap-1">
+        <button
+          type="button"
+          onClick={() => onToggleEnabled(!enabled)}
+          aria-pressed={enabled}
+          title={enabled ? 'Annotation aus' : 'Annotation an'}
+          className={
+            'flex h-8 w-8 cursor-pointer items-center justify-center rounded-full text-white shadow-lg transition ' +
+            (enabled ? 'bg-accent' : 'bg-black/60 hover:bg-black/80')
+          }
+        >
+          {enabled ? <XIcon className="h-3.5 w-3.5" /> : <PencilIcon className="h-3.5 w-3.5" />}
+        </button>
+        {enabled && (
+          <div className="flex items-center gap-1 rounded-full bg-black/60 p-1 shadow-lg">
+            {COLORS.map((c) => (
+              <button
+                key={c}
+                type="button"
+                onClick={() => setColor(c)}
+                aria-label={c}
+                aria-pressed={c === color}
+                className={
+                  'h-5 w-5 cursor-pointer rounded-full border-2 transition ' +
+                  (c === color ? 'border-white scale-110' : 'border-white/30 hover:scale-105')
+                }
+                style={{ backgroundColor: c }}
+              />
+            ))}
+          </div>
+        )}
+      </div>
+    </>
+  );
+}

apps/desktop/src/components/ScreenShareViewer.tsx

@@ -4,6 +4,7 @@ import { useTranslation } from 'react-i18next';
 
 import { type RemoteScreenShare, useCall } from '../context/CallContext';
 import { MonitorShareIcon } from './icons';
+import { ScreenShareAnnotations } from './ScreenShareAnnotations';
 
 interface ScreenShareViewerProps {
   share: RemoteScreenShare;
@@ -34,6 +35,7 @@ export function ScreenShareViewer({
   const { watchingShareUserIds, watchShare } = useCall();
   const watching = watchingShareUserIds.has(share.participantId);
   const [isFullscreen, setIsFullscreen] = useState(false);
+  const [annotateEnabled, setAnnotateEnabled] = useState(false);
   const letter = displayName.trim().charAt(0).toUpperCase() || '?';
 
   useEffect(() => {
@@ -96,6 +98,7 @@ export function ScreenShareViewer({
       </div>
 
       {watching ? (
+        <div className="relative h-full w-full flex-1">
           <video
             ref={videoRef}
             autoPlay
@@ -109,8 +112,14 @@ export function ScreenShareViewer({
             // modes (where the video covers the whole tile).
             onContextMenu={(e) => e.preventDefault()}
             onDoubleClick={toggleFullscreen}
-          className="block h-full w-full flex-1 cursor-zoom-in bg-black object-contain"
+            className="block h-full w-full cursor-zoom-in bg-black object-contain"
           />
+          <ScreenShareAnnotations
+            shareKey={share.participantId}
+            enabled={annotateEnabled}
+            onToggleEnabled={setAnnotateEnabled}
+          />
+        </div>
       ) : (
         <button
           type="button"

apps/desktop/src/components/ViewOnceImage.tsx

@@ -1,4 +1,4 @@
-import { useState } from 'react';
+import { useEffect, useRef, useState } from 'react';
 
 import { markAttachmentViewed } from '@chat-app/shared/chat';
 
@@ -16,16 +16,34 @@ interface Props {
 }
 
 // Three states:
-//   1. viewedAt is null AND user is recipient → blurred lock card; tap opens
+//   1. viewedAt is null AND user is recipient → blurred lock card. Press-and-
-//      fullscreen lightbox AND fires the mark-viewed RPC.
+//      hold reveals the image fullscreen; release closes it 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.
+//   3. user is sender → normal image, tombstone update appears once recipient
+//      burns it.
+//
+// While revealed, the renderer window enables content-protection
+// (`win.setContentProtection(true)`) so OS-level screen capture (OBS, Win/Cmd
+// snipping tools, screen recorders) sees a black/empty surface. Re-enabled
+// on release / unmount.
 export function ViewOnceImage({ attachmentId, viewedAt, isSender, src }: Props) {
   const [revealedAt, setRevealedAt] = useState<string | null>(viewedAt);
-  const [fullscreen, setFullscreen] = useState(false);
+  const [revealing, setRevealing] = useState(false);
+  const burnedRef = useRef(false);
+  const holdingRef = useRef(false);
 
   const burned = revealedAt !== null;
 
+  // Tear down screen-capture protection if the component unmounts mid-reveal.
+  useEffect(() => {
+    return () => {
+      if (revealing || holdingRef.current) {
+        void window.electronAPI?.setContentProtection?.(false).catch(() => {});
+      }
+    };
+  }, [revealing]);
+
   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">
@@ -51,35 +69,78 @@ export function ViewOnceImage({ attachmentId, viewedAt, isSender, src }: Props)
     );
   }
 
-  // Recipient, not yet viewed.
+  const startReveal = async (): Promise<void> => {
-  const handleOpen = async (): Promise<void> => {
+    if (burnedRef.current) return;
+    burnedRef.current = true;
+    holdingRef.current = true;
+    try {
+      await window.electronAPI?.setContentProtection?.(true);
+    } catch (err) {
+      console.warn('setContentProtection enable failed', err);
+    }
+    // The user may have released during the await. If so, skip showing the
+    // dialog and run the close-path directly so we don't leave the renderer
+    // in protected mode with no visible UI.
+    if (!holdingRef.current) {
+      // User released during the IPC await — endReveal already fired and is
+      // responsible for teardown (setContentProtection(false) + mark-viewed).
+      // Skipping teardown here avoids a duplicate markAttachmentViewed RPC.
+      return;
+    }
+    setRevealing(true);
+  };
+
+  const endReveal = async (): Promise<void> => {
+    if (!holdingRef.current && !revealing) return;
+    holdingRef.current = false;
+    if (revealing) setRevealing(false);
+    await teardownReveal();
+  };
+
+  const teardownReveal = async (): Promise<void> => {
+    try {
+      await window.electronAPI?.setContentProtection?.(false);
+    } catch (err) {
+      console.warn('setContentProtection disable failed', err);
+    }
     try {
       const res = await markAttachmentViewed(supabase, attachmentId);
       if (res.viewedAt) setRevealedAt(res.viewedAt);
     } catch (err) {
       console.warn('mark-viewed failed', err);
+      burnedRef.current = false;
     }
-    setFullscreen(true);
   };
 
   return (
     <>
       <button
         type="button"
-        onClick={() => void handleOpen()}
+        onPointerDown={() => void startReveal()}
-        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"
+        onPointerUp={() => void endReveal()}
+        onPointerLeave={() => void endReveal()}
+        onPointerCancel={() => void endReveal()}
+        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 select-none"
       >
         <LockIcon className="h-6 w-6 text-accent" />
-        <span className="text-xs font-medium">Einmal ansehen — antippen</span>
+        <span className="text-xs font-medium">Gedrückt halten zum Ansehen</span>
       </button>
-      {fullscreen && (
+      {revealing && (
         <div
           role="dialog"
           aria-modal="true"
-          className="fixed inset-0 z-50 flex items-center justify-center bg-black/90 p-6"
+          aria-label="Einmal-ansehen Bild"
-          onClick={() => setFullscreen(false)}
+          className="fixed inset-0 z-50 flex items-center justify-center bg-black/95 p-6"
         >
-          <img src={src} alt="" className="max-h-full max-w-full rounded-lg" />
+          <img
+            src={src}
+            alt=""
+            className="max-h-full max-w-full select-none rounded-lg"
+            draggable={false}
+          />
+          <span className="absolute bottom-6 left-1/2 -translate-x-1/2 rounded-full bg-white/10 px-3 py-1 text-xs font-semibold text-white">
+            Loslassen zum Schließen — Aufnahme blockiert
+          </span>
         </div>
       )}
     </>

apps/desktop/src/components/WhiteboardCanvas.tsx

@@ -2,6 +2,9 @@ import { useEffect, useRef, useState } from 'react';
 
 import type { WhiteboardStroke } from '@chat-app/shared/chat';
 
+import { useAuth } from '../context/AuthContext';
+import { openCursorSession, type CursorEvent, type CursorSession } from '../lib/whiteboardCursors';
+
 export type WhiteboardTool = 'pen' | 'eraser';
 export type WhiteboardColor = '#000000' | '#ef4444' | '#3b82f6' | '#22c55e' | '#facc15' | '#a855f7';
 export type WhiteboardWidth = 2 | 4 | 8;
@@ -22,6 +25,8 @@ interface Props {
   onStroke: (payload: WhiteboardStrokePayload) => void;
   logicalWidth?: number;
   logicalHeight?: number;
+  /** Enables live-cursor broadcast when set. */
+  whiteboardId?: string | null;
 }
 
 const DEFAULT_LOGICAL_W = 1280;
@@ -35,12 +40,63 @@ export function WhiteboardCanvas({
   onStroke,
   logicalWidth = DEFAULT_LOGICAL_W,
   logicalHeight = DEFAULT_LOGICAL_H,
+  whiteboardId,
 }: Props) {
   const canvasRef = useRef<HTMLCanvasElement | null>(null);
   const draftRef = useRef<WhiteboardStrokePayload | null>(null);
   const strokeStartRef = useRef<number>(0);
   const [, forceTick] = useState(0);
 
+  const { session, profile } = useAuth();
+  const [remoteCursors, setRemoteCursors] = useState<Map<string, CursorEvent & { lastSeen: number }>>(
+    () => new Map(),
+  );
+  const cursorSessionRef = useRef<CursorSession | null>(null);
+
+  useEffect(() => {
+    if (!whiteboardId) return;
+    const me = session?.user;
+    if (!me) return;
+    const displayName = profile?.displayName ?? me.email ?? me.id.slice(0, 8);
+    const s = openCursorSession(
+      whiteboardId,
+      { userId: me.id, displayName },
+      (ev) => {
+        setRemoteCursors((prev) => {
+          const next = new Map(prev);
+          next.set(ev.userId, { ...ev, lastSeen: Date.now() });
+          return next;
+        });
+      },
+    );
+    cursorSessionRef.current = s;
+    return () => {
+      s.close();
+      cursorSessionRef.current = null;
+    };
+  }, [whiteboardId, session?.user, profile?.displayName]);
+
+  // Stale-cursor sweep: drop cursors that haven't been heard from in 2s. Cheap
+  // poll because the Map is tiny (at most one entry per active collaborator).
+  useEffect(() => {
+    if (remoteCursors.size === 0) return;
+    const id = setInterval(() => {
+      const now = Date.now();
+      setRemoteCursors((prev) => {
+        let changed = false;
+        const next = new Map(prev);
+        for (const [k, v] of next) {
+          if (now - v.lastSeen > 2000) {
+            next.delete(k);
+            changed = true;
+          }
+        }
+        return changed ? next : prev;
+      });
+    }, 1000);
+    return () => clearInterval(id);
+  }, [remoteCursors.size]);
+
   useEffect(() => {
     const cv = canvasRef.current;
     if (!cv) return;
@@ -81,8 +137,9 @@ export function WhiteboardCanvas({
   };
 
   const handlePointerMove = (e: React.PointerEvent<HTMLCanvasElement>) => {
-    if (!draftRef.current) return;
     const [x, y] = canvasPoint(e);
+    cursorSessionRef.current?.send(x, y);
+    if (!draftRef.current) return;
     draftRef.current.points.push([x, y, Date.now() - strokeStartRef.current]);
     forceTick((n) => n + 1);
   };
@@ -102,6 +159,10 @@ export function WhiteboardCanvas({
   };
 
   return (
+    <div
+      className="relative"
+      style={{ aspectRatio: logicalWidth + ' / ' + logicalHeight, width: '100%' }}
+    >
       <canvas
         ref={canvasRef}
         onPointerDown={handlePointerDown}
@@ -109,9 +170,40 @@ export function WhiteboardCanvas({
         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%' }}
+        style={{ width: '100%', height: '100%' }}
       />
+      {Array.from(remoteCursors.values()).map((c) => {
+        const pctX = (c.x / logicalWidth) * 100;
+        const pctY = (c.y / logicalHeight) * 100;
+        return (
+          <div
+            key={c.userId}
+            aria-hidden="true"
+            className="pointer-events-none absolute"
+            style={{ left: pctX + '%', top: pctY + '%', transform: 'translate(-2px, -2px)' }}
+          >
+            <span
+              className="block h-2 w-2 rounded-full border-2 border-white shadow"
+              style={{ backgroundColor: colorForUserId(c.userId) }}
+            />
+            <span className="ml-2 inline-block translate-y-[-2px] rounded-full bg-black/60 px-1.5 py-0.5 text-[9px] font-semibold text-white">
+              {c.displayName}
+            </span>
+          </div>
         );
+      })}
+    </div>
+  );
+}
+
+function colorForUserId(userId: string): string {
+  // Deterministic hue from the user id so each collaborator gets a stable
+  // colour across sessions. Saturation/lightness fixed to keep the cursor
+  // legible against the white canvas.
+  let hash = 0;
+  for (let i = 0; i < userId.length; i++) hash = (hash * 31 + userId.charCodeAt(i)) | 0;
+  const hue = Math.abs(hash) % 360;
+  return 'hsl(' + hue + ', 70%, 50%)';
 }
 
 function renderStroke(

apps/desktop/src/components/WhiteboardModal.tsx

@@ -80,6 +80,7 @@ export function WhiteboardModal({ whiteboardId, onClose }: Props) {
             color={color}
             width={width}
             onStroke={(payload) => void insertStroke(payload)}
+            whiteboardId={whiteboardId}
           />
         )}
       </div>

apps/desktop/src/context/CallContext.tsx

@@ -98,6 +98,7 @@ import {
   subscribeScreenShareVolumes,
 } from '../lib/screenShareVolumes';
 import { startSoundboardHotkeys } from '../lib/soundboardHotkeys';
+import { playSoundboardLocal } from '../lib/soundboardLocalPlay';
 import { playEntry } from '../lib/soundboardPlayback';
 import {
   getPrefs as getSoundboardPrefs,
@@ -2257,15 +2258,36 @@ export function CallProvider({ children }: { children: ReactNode }) {
     pipelineRef.current?.setMonitorGain(prefs.monitorGain);
   }, []);
 
-  // Global soundboard hotkey registration — runs only while connected so the
+  // Global soundboard hotkey registration — always-on so the OS-level
-  // OS-level shortcuts don't fire when the user is outside of a call.
+  // shortcuts fire even outside a call (Stream-Deck-style local SFX). Inside
+  // a call we route through `playSoundboard` so peers hear; outside a call
+  // we fall back to `playSoundboardLocal` which plays through the system
+  // default output only.
+  //
+  // We deliberately do NOT depend on `state.kind` in the effect dep array:
+  // every call state transition (idle → connecting → connected → reconnecting
+  // → ...) would trigger a full unregister+re-register cycle through IPC, and
+  // during the 1–50 ms gap the hotkeys are silently dead. Instead we read the
+  // current call state through a ref that's always kept in sync.
+  const callStateKindRef = useRef(state.kind);
+  callStateKindRef.current = state.kind;
+  const playSoundboardRef = useRef(playSoundboard);
+  playSoundboardRef.current = playSoundboard;
+
   useEffect(() => {
-    if (state.kind !== 'connected') return;
     const teardown = startSoundboardHotkeys((id) => {
-      void playSoundboard(id);
+      if (callStateKindRef.current === 'connected') {
+        void playSoundboardRef.current(id);
+      } else {
+        void (async () => {
+          const entries = await listSoundboard();
+          const entry = entries.find((e) => e.id === id);
+          if (entry) await playSoundboardLocal(entry);
+        })();
+      }
     });
     return teardown;
-  }, [state.kind, playSoundboard]);
+  }, []); // eslint-disable-line react-hooks/exhaustive-deps
 
   const setAudioInputDevice = useCallback(async (deviceId: string | null) => {
     updateAudioSettings({ inputDeviceId: deviceId });

apps/desktop/src/lib/avatarUpload.ts

@@ -43,19 +43,86 @@ async function resizeToSquare(file: File): Promise<Blob> {
   }
 }
 
+const MAX_ANIMATED_BYTES = 2 * 1024 * 1024; // 2 MB hard cap on animated uploads
+const ANIMATED_MIMES = new Set(['image/gif', 'image/apng', 'image/webp', 'image/png']);
+
 export async function uploadAvatar(userId: string, file: File): Promise<string> {
   if (!file.type.startsWith('image/')) {
     throw new Error('only image files are accepted');
   }
+  // Animated formats bypass the canvas re-encode (which would strip
+  // animation by sampling the first frame). We still validate dimensions
+  // and size so a 40-MB animated WebP can't slip through.
+  if (ANIMATED_MIMES.has(file.type) && (await isAnimated(file))) {
+    if (file.size > MAX_ANIMATED_BYTES) {
+      throw new Error('animated avatar too large (max 2 MB)');
+    }
+    const dims = await readDimensions(file);
+    if (dims.width > MAX_DIM || dims.height > MAX_DIM) {
+      throw new Error('animated avatar exceeds ' + MAX_DIM + 'px (got ' + dims.width + 'x' + dims.height + ')');
+    }
+    return uploadAvatarBlob(userId, file);
+  }
   const blob = await resizeToSquare(file);
   return uploadAvatarBlob(userId, blob);
 }
 
+async function readDimensions(file: File): Promise<{ width: number; height: number }> {
+  const url = URL.createObjectURL(file);
+  try {
+    const img = await new Promise<HTMLImageElement>((resolve, reject) => {
+      const i = new Image();
+      i.onload = () => resolve(i);
+      i.onerror = () => reject(new Error('image load failed'));
+      i.src = url;
+    });
+    return { width: img.naturalWidth, height: img.naturalHeight };
+  } finally {
+    URL.revokeObjectURL(url);
+  }
+}
+
+async function isAnimated(file: File): Promise<boolean> {
+  // GIF: any GIF89a/GIF87a header is treated as potentially animated. The
+  // static-GIF case (one image-descriptor block) is rare enough that
+  // re-encoding wouldn't save much, so we accept the false-positives.
+  if (file.type === 'image/gif') return true;
+  // APNG: presence of an 'acTL' chunk inside the PNG stream. Scan the
+  // first 64 KB — APNGs put acTL near the front, before IDAT.
+  if (file.type === 'image/apng' || file.type === 'image/png') {
+    const head = await file.slice(0, 65536).arrayBuffer();
+    return containsBytes(head, [0x61, 0x63, 0x54, 0x4c]); // 'acTL'
+  }
+  // Animated WebP: 'ANIM' chunk in the RIFF container.
+  if (file.type === 'image/webp') {
+    const head = await file.slice(0, 65536).arrayBuffer();
+    return containsBytes(head, [0x41, 0x4e, 0x49, 0x4d]); // 'ANIM'
+  }
+  return false;
+}
+
+function containsBytes(buf: ArrayBuffer, needle: number[]): boolean {
+  const view = new Uint8Array(buf);
+  const len = view.length;
+  const nlen = needle.length;
+  outer: for (let i = 0; i + nlen <= len; i++) {
+    for (let j = 0; j < nlen; j++) {
+      if (view[i + j] !== needle[j]) continue outer;
+    }
+    return true;
+  }
+  return false;
+}
+
 // Upload an already-cropped Blob (e.g. from ImageCropDialog) without going
 // through the legacy center-crop. Caller is responsible for sizing — the
 // dialog already clamps to MAX_DIM via its outputWidth.
 export async function uploadAvatarBlob(userId: string, blob: Blob): Promise<string> {
-  const ext = blob.type === 'image/webp' ? 'webp' : 'jpg';
+  const ext =
+    blob.type === 'image/webp' ? 'webp' :
+    blob.type === 'image/gif' ? 'gif' :
+    blob.type === 'image/apng' || blob.type === 'image/png' ? 'png' :
+    'jpg';
   // Random filename so old uploads don't get overwritten before we update
   // the profile row — Supabase Storage CDN caches by URL, so a fresh path
   // also forces clients to fetch the new image.

apps/desktop/src/lib/composerDraftStore.test.ts

@@ -0,0 +1,79 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import {
+  __resetForTests,
+  clearDraft,
+  getDraftSync,
+  hasDraft,
+  hydrateDrafts,
+  setDraft,
+} from './composerDraftStore';
+
+const sqlExecuteMock = vi.fn().mockResolvedValue(undefined);
+const sqlSelectMock = vi.fn().mockResolvedValue([]);
+const sqlLoadMock = vi.fn().mockResolvedValue('mock-handle');
+
+vi.stubGlobal('window', {
+  electronAPI: {
+    platform: 'electron-chatapp-v1',
+    sqlLoad: sqlLoadMock,
+    sqlExecute: sqlExecuteMock,
+    sqlSelect: sqlSelectMock,
+  },
+});
+
+describe('composerDraftStore', () => {
+  beforeEach(() => {
+    sqlExecuteMock.mockClear();
+    sqlSelectMock.mockClear();
+    sqlLoadMock.mockClear();
+    __resetForTests();
+  });
+
+  afterEach(() => {
+    __resetForTests();
+  });
+
+  it('returns null for an unknown conversation', () => {
+    expect(getDraftSync('unknown')).toBeNull();
+    expect(hasDraft('unknown')).toBe(false);
+  });
+
+  it('stores and returns a draft synchronously after set', () => {
+    setDraft('a', { text: 'hi', replyToId: null });
+    const draft = getDraftSync('a');
+    expect(draft).not.toBeNull();
+    expect(draft?.text).toBe('hi');
+    expect(draft?.replyToId).toBeNull();
+    expect(hasDraft('a')).toBe(true);
+  });
+
+  it('isolates drafts per conversation', () => {
+    setDraft('a', { text: 'one', replyToId: null });
+    setDraft('b', { text: 'two', replyToId: 'msg-9' });
+    expect(getDraftSync('a')?.text).toBe('one');
+    expect(getDraftSync('b')?.replyToId).toBe('msg-9');
+  });
+
+  it('clearDraft removes the draft from memory', () => {
+    setDraft('a', { text: 'one', replyToId: null });
+    clearDraft('a');
+    expect(getDraftSync('a')).toBeNull();
+    expect(hasDraft('a')).toBe(false);
+  });
+
+  it('treats an empty-string text + null reply as "no draft"', () => {
+    setDraft('a', { text: '', replyToId: null });
+    expect(getDraftSync('a')).toBeNull();
+    expect(hasDraft('a')).toBe(false);
+  });
+
+  it('hydrateDrafts populates the in-memory map from SQLite rows', async () => {
+    sqlSelectMock.mockResolvedValueOnce([
+      { conversation_id: 'a', text: 'persisted', reply_to_id: 'msg-1', updated_at: '2026-05-17T00:00:00Z' },
+    ]);
+    await hydrateDrafts();
+    expect(getDraftSync('a')?.text).toBe('persisted');
+    expect(getDraftSync('a')?.replyToId).toBe('msg-1');
+  });
+});

apps/desktop/src/lib/composerDraftStore.ts

@@ -0,0 +1,160 @@
+// Composer-draft persistence. Two-tier semantics:
+//   * In-memory `Map<convId, Draft>` for instant synchronous reads on
+//     mount (mirrors the `messageMemoryCache` pattern from Phase 7).
+//   * SQLite (`composer_drafts` table, schema in `messageCache.ts`) for
+//     cross-restart persistence. Writes are debounced and fire-and-forget
+//     — losing the last 400ms of typing on a hard crash is acceptable;
+//     blocking the keystroke handler is not.
+//
+// Attachments are intentionally NOT serialized:
+//   * Files don't round-trip through SQLite cleanly (binary blobs blow
+//     up the cache size).
+//   * `replyToId` IS persisted; the consuming page looks up the actual
+//     message by id at render time.
+
+import { isTauriRuntime } from './globalShortcut';
+
+const DB_NAME = 'chatapp-cache';
+const WRITE_DEBOUNCE_MS = 400;
+
+interface Draft {
+  text: string;
+  replyToId: string | null;
+}
+
+interface DraftRow {
+  conversation_id: string;
+  text: string;
+  reply_to_id: string | null;
+  updated_at: string;
+}
+
+const drafts = new Map<string, Draft>();
+const pendingWrites = new Map<string, ReturnType<typeof setTimeout>>();
+let handlePromise: Promise<string | null> | null = null;
+
+async function getHandle(): Promise<string | null> {
+  if (handlePromise) return handlePromise;
+  if (!isTauriRuntime()) {
+    handlePromise = Promise.resolve(null);
+    return handlePromise;
+  }
+  handlePromise = (async () => {
+    try {
+      const handle = await window.electronAPI.sqlLoad({ name: DB_NAME });
+      // Self-contained DDL — the same statement also runs from
+      // `messageCache.ts`'s init path, but we don't want to depend on
+      // call order. SQLite's `CREATE TABLE IF NOT EXISTS` is idempotent
+      // so the double-creation is safe.
+      await window.electronAPI.sqlExecute({
+        handle,
+        query:
+          `CREATE TABLE IF NOT EXISTS composer_drafts (
+             conversation_id TEXT PRIMARY KEY,
+             text TEXT NOT NULL,
+             reply_to_id TEXT,
+             updated_at TEXT NOT NULL
+           )`,
+        bindings: [],
+      });
+      return handle;
+    } catch (err: unknown) {
+      console.warn('composerDraftStore: sqlLoad failed', err);
+      return null;
+    }
+  })();
+  return handlePromise;
+}
+
+export function getDraftSync(conversationId: string): Draft | null {
+  const stored = drafts.get(conversationId);
+  if (!stored) return null;
+  return { text: stored.text, replyToId: stored.replyToId };
+}
+
+export function hasDraft(conversationId: string): boolean {
+  return drafts.has(conversationId);
+}
+
+export function setDraft(conversationId: string, draft: Draft): void {
+  if (draft.text.length === 0 && draft.replyToId === null) {
+    if (drafts.has(conversationId)) {
+      drafts.delete(conversationId);
+      scheduleWrite(conversationId);
+    }
+    return;
+  }
+  drafts.set(conversationId, { text: draft.text, replyToId: draft.replyToId });
+  scheduleWrite(conversationId);
+}
+
+export function clearDraft(conversationId: string): void {
+  if (!drafts.has(conversationId)) return;
+  drafts.delete(conversationId);
+  scheduleWrite(conversationId);
+}
+
+function scheduleWrite(conversationId: string): void {
+  const existing = pendingWrites.get(conversationId);
+  if (existing) clearTimeout(existing);
+  const timer = setTimeout(() => {
+    pendingWrites.delete(conversationId);
+    void flushOne(conversationId);
+  }, WRITE_DEBOUNCE_MS);
+  pendingWrites.set(conversationId, timer);
+}
+
+async function flushOne(conversationId: string): Promise<void> {
+  const handle = await getHandle();
+  if (!handle) return;
+  const draft = drafts.get(conversationId);
+  try {
+    if (draft) {
+      await window.electronAPI.sqlExecute({
+        handle,
+        query:
+          `INSERT INTO composer_drafts (conversation_id, text, reply_to_id, updated_at)
+           VALUES ($1, $2, $3, $4)
+           ON CONFLICT(conversation_id) DO UPDATE SET
+             text = excluded.text,
+             reply_to_id = excluded.reply_to_id,
+             updated_at = excluded.updated_at`,
+        bindings: [conversationId, draft.text, draft.replyToId, new Date().toISOString()],
+      });
+    } else {
+      await window.electronAPI.sqlExecute({
+        handle,
+        query: 'DELETE FROM composer_drafts WHERE conversation_id = $1',
+        bindings: [conversationId],
+      });
+    }
+  } catch (err: unknown) {
+    console.warn('composerDraftStore: flush failed', err);
+  }
+}
+
+export async function hydrateDrafts(): Promise<void> {
+  const handle = await getHandle();
+  if (!handle) return;
+  try {
+    const rows = (await window.electronAPI.sqlSelect({
+      handle,
+      query: 'SELECT conversation_id, text, reply_to_id, updated_at FROM composer_drafts',
+      bindings: [],
+    })) as unknown as DraftRow[];
+    for (const r of rows) {
+      if (!r.conversation_id || typeof r.text !== 'string') continue;
+      if (r.text.length === 0 && r.reply_to_id === null) continue;
+      drafts.set(r.conversation_id, { text: r.text, replyToId: r.reply_to_id });
+    }
+  } catch (err: unknown) {
+    console.warn('composerDraftStore: hydrate failed', err);
+  }
+}
+
+export function __resetForTests(): void {
+  for (const t of pendingWrites.values()) clearTimeout(t);
+  pendingWrites.clear();
+  drafts.clear();
+  handlePromise = null;
+}

apps/desktop/src/lib/messageMemoryCache.test.ts

@@ -0,0 +1,61 @@
+import { afterEach, describe, expect, it } from 'vitest';
+import type { DecryptedMessage } from '@chat-app/shared/chat';
+
+import {
+  __resetForTests,
+  getCachedMessages,
+  hasCachedMessages,
+  setCachedMessages,
+} from './messageMemoryCache';
+
+function msg(id: string): DecryptedMessage {
+  return {
+    id,
+    conversationId: 'conv-1',
+    senderId: 'sender-1',
+    senderDeviceId: null,
+    replyToId: null,
+    editedAt: null,
+    deletedAt: null,
+    createdAt: '2026-05-17T00:00:00Z',
+    plaintext: 'hi ' + id,
+  };
+}
+
+describe('messageMemoryCache', () => {
+  afterEach(() => {
+    __resetForTests();
+  });
+
+  it('returns empty array when nothing is cached', () => {
+    expect(getCachedMessages('unknown')).toEqual([]);
+    expect(hasCachedMessages('unknown')).toBe(false);
+  });
+
+  it('stores and returns messages per conversation', () => {
+    setCachedMessages('a', [msg('m1'), msg('m2')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
+    expect(hasCachedMessages('a')).toBe(true);
+  });
+
+  it('isolates conversations', () => {
+    setCachedMessages('a', [msg('m1')]);
+    setCachedMessages('b', [msg('m9')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1']);
+    expect(getCachedMessages('b').map((m) => m.id)).toEqual(['m9']);
+  });
+
+  it('overwrites prior cache when set again', () => {
+    setCachedMessages('a', [msg('m1')]);
+    setCachedMessages('a', [msg('m1'), msg('m2')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
+  });
+
+  it('treats an explicit empty list as "cached"', () => {
+    // A conversation that genuinely has zero messages should still be
+    // flagged as cached so the hook skips the loading spinner on re-entry.
+    setCachedMessages('a', []);
+    expect(hasCachedMessages('a')).toBe(true);
+    expect(getCachedMessages('a')).toEqual([]);
+  });
+});

apps/desktop/src/lib/messageMemoryCache.ts

@@ -0,0 +1,37 @@
+// In-memory cache of the most-recently-rendered messages for each
+// conversation. Survives React component unmount/remount (used by
+// `useConversationMessages` to initialize state synchronously when
+// ConversationPage is remounted on chat switch). Session-scoped — lost
+// on full app reload. The SQLite cache (`messageCache.ts`) is still the
+// source of truth for cross-session persistence; this layer just shaves
+// off the round-trip-to-disk spinner flash.
+//
+// Two-tier semantics:
+//   * `hasCachedMessages(id)` returns true even for a known-empty chat
+//     so the hook can suppress the loading spinner on re-entry.
+//   * `getCachedMessages(id)` returns a defensive copy so callers can't
+//     mutate the cached array.
+
+import type { DecryptedMessage } from '@chat-app/shared/chat';
+
+const cache = new Map<string, DecryptedMessage[]>();
+
+export function getCachedMessages(conversationId: string): DecryptedMessage[] {
+  const stored = cache.get(conversationId);
+  return stored ? stored.slice() : [];
+}
+
+export function hasCachedMessages(conversationId: string): boolean {
+  return cache.has(conversationId);
+}
+
+export function setCachedMessages(
+  conversationId: string,
+  messages: DecryptedMessage[],
+): void {
+  cache.set(conversationId, messages.slice());
+}
+
+export function __resetForTests(): void {
+  cache.clear();
+}

apps/desktop/src/lib/soundboardLocalPlay.ts

@@ -0,0 +1,44 @@
+// Plays a soundboard entry to the local default audio output. Used when no
+// call pipeline is active (the in-call path routes via the LiveKit
+// publishing pipeline so peers hear; this path is local-only). Fetches the
+// blob via getSoundBlob and creates a short-lived object URL for the audio
+// element.
+
+import { getSoundBlob, type SoundboardEntry } from './soundboardStorage';
+
+const activeAudios = new Set<HTMLAudioElement>();
+
+export async function playSoundboardLocal(entry: SoundboardEntry): Promise<void> {
+  const blob = await getSoundBlob(entry.id);
+  if (!blob) return;
+  const src = URL.createObjectURL(blob);
+  const el = new Audio(src);
+  // Use the per-entry gain as local volume. SoundboardEntry exposes `gain`
+  // (0..1) which mirrors the value used in the in-call pipeline.
+  el.volume = Math.max(0, Math.min(1, entry.gain));
+  activeAudios.add(el);
+  const cleanup = () => {
+    activeAudios.delete(el);
+    URL.revokeObjectURL(src);
+  };
+  el.addEventListener('ended', cleanup);
+  el.addEventListener('error', cleanup);
+  try {
+    await el.play();
+  } catch (err) {
+    cleanup();
+    console.warn('soundboardLocalPlay failed', err);
+  }
+}
+
+export function stopSoundboardLocal(): void {
+  for (const el of activeAudios) {
+    try {
+      el.pause();
+      el.currentTime = 0;
+    } catch {
+      /* ignore */
+    }
+  }
+  activeAudios.clear();
+}

apps/desktop/src/lib/useConversationMessages.ts

@@ -1,16 +1,16 @@
-import { fetchPeerPublicKeys } from '@chat-app/shared/auth';
 import {
   type AttachmentHandle,
+  clearConvKeyCache,
   type DecryptedMessage,
   decryptMessages,
   encryptAndUploadAttachment,
   fetchConversationMessages,
+  getOrCreateConvKey,
   insertAttachmentRow,
   MAX_ATTACHMENT_BYTES,
   type MessageWithCipher,
+  rotateConvKey,
   sendEncryptedMessage,
-  shareConvKeyToUser,
-  tryGetConvKey,
 } from '@chat-app/shared/chat';
 import { bytesToPgHex, pgBytesToBytes } from '@chat-app/shared/supabase';
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
@@ -33,6 +33,11 @@ import {
   shouldGiveUp,
   subscribeOutbox,
 } from './messageOutbox';
+import {
+  getCachedMessages,
+  hasCachedMessages,
+  setCachedMessages,
+} from './messageMemoryCache';
 import { supabase } from './supabase';
 import { cachedUserKey } from './userIdentity';
 
@@ -82,7 +87,20 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
   retryPending: (id: string) => void;
   cancelPending: (id: string) => void;
 } {
-  const [state, setState] = useState<State>({ messages: [], loading: true, error: null });
+  // Initialize from the in-memory cache so a previously-viewed chat shows
+  // content on the very first render after the parent remounts on `:id`
+  // change. `loading` stays true ONLY for never-seen conversations (cache
+  // miss) so the spinner doesn't flash on every chat switch.
+  const [state, setState] = useState<State>(() => {
+    if (conversationId && hasCachedMessages(conversationId)) {
+      return {
+        messages: getCachedMessages(conversationId),
+        loading: false,
+        error: null,
+      };
+    }
+    return { messages: [], loading: true, error: null };
+  });
   const [pending, setPending] = useState<OutboxItem[]>(() =>
     conversationId ? getOutbox(conversationId) : [],
   );
@@ -107,12 +125,25 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
     });
   }, [userId]);
 
-  // Proactive rewrap sweep: when a conversation opens, walk every accepted
+  // Proactive rewrap sweep: when a conversation opens, ensure the active
-  // member and ensure the active conv-key has a `recipient_user_id` bundle
+  // conv-key has a `recipient_user_id` bundle for every accepted member.
-  // for them. Members who are missing one (typically peers who haven't yet
+  //
-  // migrated to the per-user key model) get a best-effort wrap from the
+  // If any peer is missing a bundle at the active version, the previous
-  // local conv-key handle. Closes the legacy migration gap so peer B can
+  // implementation called `shareConvKeyToUser` for each missing peer —
-  // read on first unlock without manual intervention from A.
+  // that helper reads from the module-level conv-key cache first, and if
+  // the cache held a STALE locally-generated key (from a buggy bootstrap
+  // race in an earlier app version), the stale key got propagated to the
+  // peer's row. Both sides then encrypt with mutually un-mergeable keys
+  // and every message is "Nachricht nicht lesbar" forever (incident:
+  // conv aae12d84).
+  //
+  // The replacement: when any peer is missing, call `rotateConvKey` once.
+  // Rotation generates a fresh symmetric key locally, fetches each member's
+  // CURRENT pubkey, wraps the fresh key for everyone, and atomically bumps
+  // `active_key_version` via the `rotate_conv_key` RPC (FOR UPDATE lock
+  // serialises concurrent rotations). This bypasses the cache entirely:
+  // the new version's cache entry is the just-rotated key, and the stale
+  // entry at the old version is irrelevant because nobody reads it any more.
   useEffect(() => {
     if (!conversationId || !userId) return;
     let cancelled = false;
@@ -136,31 +167,41 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
         // db-types snapshot predates the active_key_version column; cast via unknown.
         const version = (convRow as unknown as { active_key_version: number }).active_key_version;
 
-        const handle = await tryGetConvKey(supabase, conversationId, userId, priv, version);
+        // First, make sure we have a usable handle for the active version
-        if (!handle || cancelled) return;
+        // (this auto-rotates if we're locked out of our own bundle — the
+        // recovery path added in v0.21.1/v0.21.2).
+        const handle = await getOrCreateConvKey(supabase, conversationId, {
+          userId,
+          privateKey: priv,
+        });
+        if (cancelled) return;
+        if (handle.keyVersion > version) return; // already rotated by helper
 
+        // Check membership state on the server.
         const { data: members, error: mErr } = await supabase
           .from('conversation_members')
           .select('user_id, accepted')
           .eq('conversation_id', conversationId);
         if (mErr || !members) return;
-        const memberIds = (members as Array<{ user_id: string; accepted: boolean }>)
+        const peerIds = (members as Array<{ user_id: string; accepted: boolean }>)
           .filter((m) => m.accepted && m.user_id !== userId)
           .map((m) => m.user_id);
-        if (memberIds.length === 0) return;
+        if (peerIds.length === 0) return;
 
-        const peers = await fetchPeerPublicKeys(supabase, memberIds);
+        // Count how many of the peers have a recipient_user_id bundle at
-        for (const peer of peers) {
+        // the active version. If any are missing, rotate to V+1 — the
-          if (cancelled) return;
+        // rotation will wrap a fresh key for every accepted member with a
-          const { count, error: cntErr } = await (
+        // user_keys row.
+        const { data: existingRows, error: rowsErr } = await (
           supabase as unknown as {
             from: (t: string) => {
-                select: (s: string, o?: object) => {
+              select: (s: string) => {
-                  eq: (...a: unknown[]) => {
+                eq: (c: string, v: string) => {
-                    eq: (...a: unknown[]) => {
+                  eq: (c: string, v: number) => {
-                      eq: (
+                    in: (c: string, v: string[]) => Promise<{
-                        ...a: unknown[]
+                      data: Array<{ recipient_user_id: string }> | null;
-                      ) => Promise<{ count: number | null; error: unknown }>;
+                      error: unknown;
+                    }>;
                   };
                 };
               };
@@ -168,24 +209,34 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           }
         )
           .from('conversation_keys')
-            .select('recipient_user_id', { count: 'exact', head: true })
+          .select('recipient_user_id')
           .eq('conversation_id', conversationId)
-            .eq('recipient_user_id', peer.userId)
+          .eq('key_version', version)
-            .eq('key_version', version);
+          .in('recipient_user_id', peerIds);
-          if (cntErr) continue;
+        if (rowsErr) return;
-          if ((count ?? 0) === 0) {
+        const wrappedPeerIds = new Set(
-            try {
+          (existingRows ?? []).map((r) => r.recipient_user_id),
-              await shareConvKeyToUser(
-                supabase,
-                conversationId,
-                peer.userId,
-                peer.publicKey,
-                { userId, privateKey: priv },
         );
+        const missing = peerIds.filter((id) => !wrappedPeerIds.has(id));
+        if (missing.length === 0) return;
+
+        // At least one peer is missing a bundle — rotate. We deliberately do
+        // NOT use the cached conv-key here. The rotation generates a fresh
+        // key wrapped to every current member's CURRENT pubkey, so any
+        // staleness in the local cache for the OLD version is irrelevant
+        // going forward.
+        try {
+          await rotateConvKey(supabase, conversationId, {
+            userId,
+            privateKey: priv,
+          });
         } catch (err) {
-              console.warn('proactive rewrap failed for', peer.userId, err);
+          // Most likely cause: a concurrent peer also called rotate and
-            }
+          // won the race; their bumped active_key_version makes our
-          }
+          // `p_new_version <= cur_version` and the RPC raises. That's fine —
+          // the next chat-open / send will fetch the new active version and
+          // unwrap the bundle that peer wrapped for us.
+          console.warn('proactive rotate failed (likely concurrent rotation)', err);
         }
       } catch (err) {
         console.warn('proactive rewrap sweep failed', err);
@@ -229,6 +280,7 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
       const rows = await fetchConversationMessages(supabase, conversationId);
       const decrypted = await decryptBatch(rows);
       setState({ messages: decrypted, loading: false, error: null });
+      setCachedMessages(conversationId, decrypted);
       // Persist the fresh batch to the local cache so next conversation
       // switch / app start can hydrate instantly. Fire-and-forget — cache
       // write failure is never user-visible.
@@ -248,12 +300,17 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
   // when the server response lands. On cache-miss this is a ~5ms no-op.
   useEffect(() => {
     if (!conversationId) return;
+    // Memory cache already populated state synchronously — skip the disk
+    // round-trip entirely. The canonical data lands shortly via refresh();
+    // the SQLite cache only matters for cold-start hydration.
+    if (hasCachedMessages(conversationId)) return;
     let cancelled = false;
     void loadCachedMessages(conversationId).then((cached) => {
       if (cancelled || cached.length === 0) return;
       setState((prev) => {
         // Don't clobber a fresh server response that already landed.
         if (prev.messages.length > 0) return prev;
+        setCachedMessages(conversationId, cached);
         return { messages: cached, loading: false, error: null };
       });
     });
@@ -338,7 +395,9 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
       if (!decrypted) return;
       setState((prev) => {
         if (prev.messages.some((m) => m.id === decrypted!.id)) return prev;
-        return { ...prev, messages: [...prev.messages, decrypted!] };
+        const next = [...prev.messages, decrypted!];
+        if (conversationId) setCachedMessages(conversationId, next);
+        return { ...prev, messages: next };
       });
     },
     [conversationId, deviceId, decryptBatch],
@@ -358,6 +417,7 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           editedAt: partial.editedAt,
           deletedAt: partial.deletedAt,
         };
+        if (conversationId) setCachedMessages(conversationId, next);
         return { ...prev, messages: next };
       });
       if (partial.editedAt && !partial.deletedAt) {
@@ -421,6 +481,7 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           if (idx === -1) return prev;
           const next = [...prev.messages];
           next[idx] = decrypted!;
+          if (conversationId) setCachedMessages(conversationId, next);
           return { ...prev, messages: next };
         });
       }
@@ -428,25 +489,32 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
     [conversationId, deviceId, decryptBatch],
   );
 
-  const handleDelete = useCallback((row: Record<string, unknown>) => {
+  const handleDelete = useCallback(
+    (row: Record<string, unknown>) => {
       const id = String(row.id);
-    setState((prev) => ({
+      setState((prev) => {
-      ...prev,
+        const next = prev.messages.filter((m) => m.id !== id);
-      messages: prev.messages.filter((m) => m.id !== id),
+        if (conversationId) setCachedMessages(conversationId, next);
-    }));
+        return { ...prev, messages: next };
+      });
       void deleteCachedMessage(id);
-  }, []);
+    },
+    [conversationId],
+  );
 
   useEffect(() => {
     if (!conversationId || !userId || !deviceId) return;
     void refresh();
 
     // Batch INSERT bursts so a paste / backfill doesn't fire N parallel
-    // refetches + decrypts. If more than BATCH_BURST_THRESHOLD ids arrive
+    // refetches + decrypts. The first event in a quiet period fires
-    // within BATCH_WINDOW_MS, collapse to a single refresh() which pulls
+    // `handleInsert` immediately so single incoming messages don't sit
-    // the last 100 in one query — cheaper and keeps order stable. For
+    // behind a debounce timer (previous behaviour: 250 ms blank between
-    // lone inserts the per-id path stays so latency is unchanged.
+    // notification-sound and message body). Subsequent events arriving
-    const BATCH_WINDOW_MS = 250;
+    // within BATCH_WINDOW_MS of the first are buffered; if the burst grows
+    // past BATCH_BURST_THRESHOLD the buffered tail collapses into one
+    // `refresh()` instead of N individual refetches.
+    const BATCH_WINDOW_MS = 80;
     const BATCH_BURST_THRESHOLD = 3;
     let burstBuffer: Array<Record<string, unknown>> = [];
     let burstTimer: number | null = null;
@@ -465,6 +533,15 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
       }
     };
     const queueInsert = (row: Record<string, unknown>) => {
+      if (burstBuffer.length === 0 && burstTimer === null) {
+        // First event in a quiet period — fire immediately so the user sees
+        // the message right when they hear the notification sound. Arm a
+        // short window in case a burst follows; follow-ups go through the
+        // buffer and may collapse into a refresh.
+        void handleInsert(row);
+        burstTimer = window.setTimeout(flushBurst, BATCH_WINDOW_MS);
+        return;
+      }
       burstBuffer.push(row);
       if (burstTimer === null) {
         burstTimer = window.setTimeout(flushBurst, BATCH_WINDOW_MS);
@@ -491,18 +568,46 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           }
         },
       )
-      // When a peer device wraps the conversation-key for us (e.g. we just
+      // Any conversation_keys change for this conv invalidates the cached
-      // registered a fresh device), re-decrypt the visible messages.
+      // conv-key for the affected version. The module-level cache in
+      // shared/chat/convKeys.ts otherwise holds the previously-unwrapped key
+      // forever within a session — which is exactly what propagated the
+      // stale local bootstrap key in conv aae12d84, recreating divergent
+      // bundles after a server-side cleanup. Clearing on any INSERT/UPDATE/
+      // DELETE for the conv forces the next `getOrCreateConvKey` /
+      // `tryGetConvKey` call to re-fetch the canonical bundle from the
+      // server. Cheap (a single Map.delete), defensive, and avoids stale-
+      // cache propagation across all of {peer rotation, device wrap, admin
+      // cleanup}.
+      //
+      // We also keep the historical "device wrap → refresh" trigger so a
+      // freshly-registered device of our own re-decrypts in place.
       .on(
         'postgres_changes',
         {
-          event: 'INSERT',
+          event: '*',
           schema: 'public',
           table: 'conversation_keys',
           filter: 'conversation_id=eq.' + conversationId,
         },
-        (payload: { new: { recipient_device_id?: string } }) => {
+        (payload: {
-          if (payload.new?.recipient_device_id === deviceId) {
+          eventType: 'INSERT' | 'UPDATE' | 'DELETE';
+          new: { recipient_device_id?: string; key_version?: number };
+          old: { recipient_device_id?: string; key_version?: number };
+        }) => {
+          const v =
+            payload.eventType === 'DELETE'
+              ? payload.old?.key_version
+              : payload.new?.key_version;
+          if (typeof v === 'number') {
+            clearConvKeyCache(conversationId, v);
+          } else {
+            clearConvKeyCache(conversationId);
+          }
+          if (
+            payload.eventType === 'INSERT' &&
+            payload.new?.recipient_device_id === deviceId
+          ) {
             void refresh();
           }
         },
@@ -552,13 +657,12 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
       });
       setState((prev) => {
         if (prev.messages.some((m) => m.id === msg.id)) return prev;
-        return {
+        const next = [
-          ...prev,
-          messages: [
           ...prev.messages,
           { ...msg, plaintext: text } as DecryptedMessage,
-          ],
+        ];
-        };
+        setCachedMessages(convId, next);
+        return { ...prev, messages: next };
       });
     },
     [],
@@ -686,16 +790,15 @@ export function useConversationMessages({ conversationId, userId, deviceId }: Ar
           : JSON.stringify({ v: 1, text: trimmed, attachments: handles });
       setState((prev) => {
         if (prev.messages.some((m) => m.id === msg.id)) return prev;
-        return {
+        const next = [
-          ...prev,
-          messages: [
           ...prev.messages,
           {
             ...msg,
             plaintext: attachmentsPayload,
           } as DecryptedMessage,
-          ],
+        ];
-        };
+        setCachedMessages(conversationId, next);
+        return { ...prev, messages: next };
       });
 
       // 4. Insert public attachment metadata rows pointing at the new message.

apps/desktop/src/lib/voiceSpeedSettings.ts

@@ -0,0 +1,29 @@
+// Persists the preferred voice-message playback rate across sessions.
+// localStorage is fine here — non-sensitive, single source of truth per
+// device, no cross-device sync needed.
+
+const KEY = 'chatapp:voice-speed';
+const ALLOWED = [1, 1.5, 2] as const;
+export type VoiceSpeed = (typeof ALLOWED)[number];
+
+export function getVoiceSpeed(): VoiceSpeed {
+  try {
+    const raw = window.localStorage.getItem(KEY);
+    if (!raw) return 1;
+    const parsed = Number(raw);
+    if (ALLOWED.includes(parsed as VoiceSpeed)) return parsed as VoiceSpeed;
+  } catch {
+    /* localStorage unavailable */
+  }
+  return 1;
+}
+
+export function setVoiceSpeed(speed: VoiceSpeed): void {
+  try {
+    window.localStorage.setItem(KEY, String(speed));
+  } catch {
+    /* localStorage unavailable — best effort */
+  }
+}
+
+export const VOICE_SPEEDS = ALLOWED;

apps/desktop/src/lib/whiteboardCursors.ts

@@ -0,0 +1,81 @@
+// Live-cursor pubsub for the multi-user whiteboard. Uses Supabase's
+// `broadcast` channel rather than `presence` because we want fire-and-forget
+// position updates (no need to track join/leave) and presence has higher
+// minimum latency due to its diff-and-merge semantics.
+//
+// Throttled to ~30 fps so a continuous drag doesn't flood the channel.
+
+import type { RealtimeChannel } from '@supabase/supabase-js';
+
+import { supabase } from './supabase';
+
+const THROTTLE_MS = 33; // ~30 fps
+
+export interface CursorEvent {
+  userId: string;
+  displayName: string;
+  // logical canvas coordinates (matches WhiteboardCanvas internal space)
+  x: number;
+  y: number;
+}
+
+export interface CursorSession {
+  send: (x: number, y: number) => void;
+  close: () => void;
+}
+
+export function openCursorSession(
+  whiteboardId: string,
+  self: { userId: string; displayName: string },
+  onCursor: (ev: CursorEvent) => void,
+): CursorSession {
+  const channel: RealtimeChannel = supabase.channel('wb-cursor:' + whiteboardId, {
+    config: { broadcast: { self: false } },
+  });
+  channel.on('broadcast', { event: 'cursor' }, (payload) => {
+    const ev = payload.payload as CursorEvent | undefined;
+    if (!ev || ev.userId === self.userId) return;
+    onCursor(ev);
+  });
+  channel.subscribe();
+
+  let lastSentAt = 0;
+  let pending: { x: number; y: number } | null = null;
+  let flushTimer: ReturnType<typeof setTimeout> | null = null;
+
+  const flush = (): void => {
+    flushTimer = null;
+    if (!pending) return;
+    const { x, y } = pending;
+    pending = null;
+    lastSentAt = Date.now();
+    void channel.send({
+      type: 'broadcast',
+      event: 'cursor',
+      payload: { userId: self.userId, displayName: self.displayName, x, y } satisfies CursorEvent,
+    });
+  };
+
+  const send = (x: number, y: number): void => {
+    const now = Date.now();
+    const since = now - lastSentAt;
+    if (since >= THROTTLE_MS) {
+      pending = { x, y };
+      flush();
+    } else {
+      pending = { x, y };
+      if (flushTimer === null) {
+        flushTimer = setTimeout(flush, THROTTLE_MS - since);
+      }
+    }
+  };
+
+  const close = (): void => {
+    if (flushTimer !== null) clearTimeout(flushTimer);
+    flushTimer = null;
+    pending = null;
+    void supabase.removeChannel(channel);
+  };
+
+  return { send, close };
+}

apps/desktop/src/pages/ConversationPage.tsx

@@ -78,6 +78,7 @@ import { markRead as markMessagesReadRemote, useMessageReads } from '../lib/useM
 import { usePeerPresence } from '../lib/usePeerPresence';
 import { usePinnedMessages } from '../lib/usePinnedMessages';
 import { useTypingChannel } from '../lib/useTypingChannel';
+import { clearDraft, getDraftSync, setDraft } from '../lib/composerDraftStore';
 
 // Discriminated union for rows inside the virtualized message list. Keeping
 // pending bubbles and the "load older" tile inside the same Virtuoso
@@ -94,18 +95,18 @@ type VirtuosoRow =
 // change on every parent render.
 const EMPTY_REACTIONS: AggregatedReaction[] = [];
 
-// Per-conversation scroll memory. Module-scoped so it survives re-mounts
+// Per-conversation scroll memory. Module-scoped so it survives the
-// of ConversationPage when the route param (`id`) changes — switching
+// per-id remount of ConversationPage (see `ConversationRoute` in
-// chats unmounts/remounts the page in our router setup. Session-only
+// App.tsx). Session-only (lost on reload, like Discord). The
-// (lost on reload, like Discord). The `stickToBottom` flag is preserved
+// `stickToBottom` flag is preserved alongside the topmost-visible row
-// alongside the topmost-visible row index so a chat the user left at the
+// index so a chat the user left at the bottom keeps auto-following new
-// bottom keeps auto-following new messages when they return; a chat
+// messages when they return; a chat scrolled up returns to roughly the
-// scrolled up returns to roughly the same row the user was reading.
+// same row the user was reading.
 //
 // We track the topmost-visible row index rather than a pixel `scrollTop`
 // because `react-virtuoso` virtualizes the list — the underlying scroll
 // element's pixel offset depends on dynamically-measured row heights and
-// is not stable across re-mounts. Using a row index restores the user's
+// is not stable across remounts. Using a row index restores the user's
 // reading position even if some rows above re-render at different heights.
 const scrollPositions = new Map<string, { topmostIndex: number; stickToBottom: boolean }>();
 
@@ -200,7 +201,10 @@ export function ConversationPage() {
     });
   }, [id, messages, myId]);
 
-  const [text, setText] = useState('');
+  const [text, setText] = useState<string>(() => {
+    if (!id) return '';
+    return getDraftSync(id)?.text ?? '';
+  });
   const [sending, setSending] = useState(false);
   const [sendError, setSendError] = useState<string | null>(null);
   const [stickToBottom, setStickToBottom] = useState(true);
@@ -305,19 +309,19 @@ export function ConversationPage() {
   const composerRef = useRef<HTMLTextAreaElement>(null);
 
   useEffect(() => {
-    setReplyTo(null);
+    if (!id) return;
-    setForwardTarget(null);
+    const draft = getDraftSync(id);
-    setSearchOpen(false);
+    const savedReplyToId = draft?.replyToId ?? null;
-    setMediaDrawerOpen(false);
+    if (!savedReplyToId) return;
-    setPollDialogOpen(false);
+    if (replyTo?.id === savedReplyToId) return;
-    setSearchQuery('');
+    const match = messages.find((m) => m.id === savedReplyToId);
-    setDisplayCount(150);
+    if (match) setReplyTo(match);
-    setFirstUnreadId(null);
+  }, [id, messages, replyTo?.id]);
-    setFirstUnreadJumpDismissed(false);
+
-    setNewMessagesWhileAway(0);
+  useEffect(() => {
-    previousMessageIdsRef.current = new Set();
+    if (!id) return;
-    firstUnreadComputedRef.current = false;
+    setDraft(id, { text, replyToId: replyTo?.id ?? null });
-  }, [id]);
+  }, [id, text, replyTo?.id]);
 
   useEffect(() => {
     if (firstUnreadComputedRef.current) return;
@@ -733,7 +737,12 @@ export function ConversationPage() {
   // now, so we have to call it explicitly. Tracked via a ref so we only
   // scroll when the count actually grew (not on every render where it
   // happens to be > 0).
-  const lastPendingCountRef = useRef(0);
+  // Initialize from the current pending count rather than 0 so we don't
+  // fire scrollToIndex(LAST) on the very first render of a chat that
+  // already has outbox-queued items. Only growth of `pending.length`
+  // across renders should trigger the snap-to-bottom (i.e., the user
+  // just submitted something new).
+  const lastPendingCountRef = useRef(pending.length);
   useEffect(() => {
     if (pending.length > lastPendingCountRef.current) {
       virtuosoRef.current?.scrollToIndex({
@@ -745,6 +754,24 @@ export function ConversationPage() {
     lastPendingCountRef.current = pending.length;
   }, [pending.length]);
 
+  // Snap the viewport back to the bottom after a send. The composer
+  // shrinks (cleared text, dismissed reply preview, dropped attachment
+  // thumbs) which lets the Virtuoso area grow vertically — leaving the
+  // just-sent bubble visibly above the new bottom for a frame.
+  // `requestAnimationFrame` defers the scroll until React has committed
+  // the composer-height change, so Virtuoso's ResizeObserver has
+  // already seen the new viewport and `index: 'LAST', align: 'end'`
+  // targets the correct bottom edge.
+  const snapToBottom = useCallback(() => {
+    window.requestAnimationFrame(() => {
+      virtuosoRef.current?.scrollToIndex({
+        index: 'LAST',
+        align: 'end',
+        behavior: 'auto',
+      });
+    });
+  }, []);
+
   async function handleSend(e?: React.FormEvent) {
     e?.preventDefault();
     if ((!text.trim() && attachments.length === 0) || sending) return;
@@ -763,6 +790,8 @@ export function ConversationPage() {
       if (fileInputRef.current) fileInputRef.current.value = '';
       setStickToBottom(true);
       notifyStopTyping();
+      if (id) clearDraft(id);
+      snapToBottom();
     } catch (err: unknown) {
       const code = extractErrorCode(err);
       setSendError(
@@ -788,13 +817,14 @@ export function ConversationPage() {
         setReplyTo(null);
         setStickToBottom(true);
         notifyStopTyping();
+        snapToBottom();
       } catch (err: unknown) {
         setPollError(err instanceof Error ? err.message : 'Umfrage konnte nicht gesendet werden');
       } finally {
         setPollSending(false);
       }
     },
-    [send, replyTo?.id, notifyStopTyping],
+    [send, replyTo?.id, notifyStopTyping, snapToBottom],
   );
 
   const handleCreateWhiteboard = useCallback(async () => {
@@ -807,12 +837,13 @@ export function ConversationPage() {
       setReplyTo(null);
       setStickToBottom(true);
       setOpenWhiteboardId(board.id);
+      snapToBottom();
     } catch (err: unknown) {
       setSendError(err instanceof Error ? err.message : 'Whiteboard konnte nicht angelegt werden');
     } finally {
       setCreatingWhiteboard(false);
     }
-  }, [id, creatingWhiteboard, send, replyTo?.id]);
+  }, [id, creatingWhiteboard, send, replyTo?.id, snapToBottom]);
 
   const handleStartWatchTogether = useCallback(async () => {
     if (!id) return;
@@ -832,12 +863,13 @@ export function ConversationPage() {
       setWatchDialogOpen(false);
       setWatchUrl('');
       setOpenWatchSessionId(ws.id);
+      snapToBottom();
     } catch (err: unknown) {
       setWatchError(err instanceof Error ? err.message : 'Konnte Watch-Together nicht starten');
     } finally {
       setWatchCreating(false);
     }
-  }, [id, watchUrl, send, replyTo?.id]);
+  }, [id, watchUrl, send, replyTo?.id, snapToBottom]);
 
   const handleStartGame = useCallback(async (gameType: GameType) => {
     if (!id) return;
@@ -864,12 +896,13 @@ export function ConversationPage() {
       setStickToBottom(true);
       setGameDialogOpen(false);
       setOpenGameId(game.id);
+      snapToBottom();
     } catch (err: unknown) {
       setGameError(err instanceof Error ? err.message : 'Konnte Spiel nicht starten');
     } finally {
       setGameCreating(false);
     }
-  }, [id, conversation, myId, send, replyTo?.id]);
+  }, [id, conversation, myId, send, replyTo?.id, snapToBottom]);
 
   async function ingestFiles(files: File[]) {
     const compressed = await compressImages(files);
@@ -1036,14 +1069,32 @@ export function ConversationPage() {
             // the bottom; returning `false` from the callback when they're
             // scrolled up preserves their reading position when realtime
             // messages arrive (critical UX: do NOT jerk the user).
-            followOutput={(isAtBottom) => (isAtBottom ? 'smooth' : false)}
+            //
+            // We deliberately use 'auto' (instant) rather than 'smooth':
+            // with a smooth scroll animation, atBottomStateChange fires
+            // `false` mid-animation (scrollTop is briefly above the new
+            // bottom) and then `true` after settle — that flips
+            // stickToBottom twice, flashing the "Zum neuesten" pill and
+            // re-rendering the whole list. Instant scroll has zero
+            // mid-animation state so the cascade never happens.
+            followOutput={(isAtBottom) => (isAtBottom ? 'auto' : false)}
             atBottomStateChange={handleAtBottomStateChange}
-            atBottomThreshold={80}
+            // 250 px tolerance — large enough that appending a tall row
+            // (image, voice note, grouped attachments) doesn't push the
+            // user out of the at-bottom zone. The previous 80 px flipped
+            // stickToBottom on nearly every typical message arrival.
+            atBottomThreshold={250}
             rangeChanged={handleRangeChanged}
             startReached={handleStartReached}
             // Render rows just outside the viewport so fast scrolling
             // doesn't briefly flash empty space.
             increaseViewportBy={400}
+            // Visual breathing space below the last message so a bubble
+            // bottom doesn't sit flush against the composer top — matches
+            // Discord's chat-pane bottom padding.
+            components={{
+              Footer: () => <div style={{ height: '12px' }} />,
+            }}
             itemContent={(_index, row) => {
               if (row.kind === 'loader') {
                 return (

apps/mobile/.gitignore

@@ -0,0 +1,6 @@
+
+# @generated expo-cli sync-2b81b286409207a5da26e14c78851eb30d8ccbdb
+# The following patterns were generated by expo-cli
+
+expo-env.d.ts
+# @end expo-cli

docs/superpowers/plans/2026-05-17-chat-switch-flicker.md

@@ -0,0 +1,703 @@
+# Chat-Switch Flicker — Fix 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:** Eliminate the visible flicker / scroll-jump when switching between conversations so the transition matches Discord's "instant content swap" feel.
+
+**Architecture:** Two complementary fixes that, together, kill seven independent state-bleed root causes:
+
+1. **Force a fresh `ConversationPage` instance per `:id` route param** via a wrapper component that reads `useParams` and passes `key={id}`. Today the same React component instance handles every conversation because React Router does not remount the route element when only a param changes — that is what lets chat A's state (messages, scroll position, composer drafts, Virtuoso scroll cache) bleed into chat B's first render.
+2. **Add a module-scoped in-memory cache** (`Map<convId, DecryptedMessage[]>`) in `useConversationMessages` so the freshly-mounted hook starts with prior data synchronously on the first render. SQLite cache still hydrates async for never-seen chats. Net effect: instant content for any previously-visited chat, no spinner-flash.
+
+**Tech Stack:** React 18, React Router v6 (v7_startTransition opt-in), react-virtuoso, better-sqlite3 (Electron main-process bridge via `window.electronAPI.sql*`), Vitest.
+
+---
+
+## Root-Cause Findings (Phase 1 evidence)
+
+| # | Symptom | File:line | Why it happens |
+|---|---------|-----------|----------------|
+| RC1 | **Ghost messages of previous chat** for 50–300 ms | `apps/desktop/src/lib/useConversationMessages.ts:85, 220-243, 249-263` | `useState<State>({messages: [], loading: true})` only runs on first mount. On `conversationId` change, the state still holds chat A's messages; `refresh()` skips `loading: true` because `prev.messages.length > 0`; the cache effect also bails (`if (prev.messages.length > 0) return prev`). Chat A's data renders under chat B's id until the network round-trip finishes. |
+| RC2 | **Scroll jumps to wrong row** on switch | `apps/desktop/src/pages/ConversationPage.tsx:1023, 1034, 470-481` | Virtuoso instance is preserved across switches (parent isn't remounted). `initialTopMostItemIndex` is only honoured on Virtuoso's first mount, so chat A's last scroll position is what Virtuoso tries to keep when chat B's rows replace chat A's. |
+| RC3 | **Saved positions corrupted across switches** | `apps/desktop/src/pages/ConversationPage.tsx:705-716` | While chat A's rows are still rendered under chat B's id (RC1 window), `rangeChanged` fires for chat A's visible range and writes the index into `scrollPositions[chatBid]`. Next time you re-enter chat B, it restores chat A's row index. |
+| RC4 | **Stale composer / reply / search / unread state** for one render | `apps/desktop/src/pages/ConversationPage.tsx:307-320` | `useEffect([id])` resets `replyTo`, `displayCount`, `firstUnreadId`, etc. — but effects fire **after** the first render of the new id. The first paint of chat B briefly shows chat A's reply preview and `displayCount`. |
+| RC5 | **Phantom scroll-to-bottom** after switching | `apps/desktop/src/pages/ConversationPage.tsx:736-746` | `lastPendingCountRef` is never reset per-chat. Switching from a chat with 0 pending to a chat with N pending triggers `pending.length > lastPendingCountRef.current` → `scrollToIndex(LAST)` even though that pending state was always there. |
+| RC6 | **`newMessagesWhileAway` briefly off** | `apps/desktop/src/pages/ConversationPage.tsx:335-346` | `previousMessageIdsRef.current` contains chat A's ids on the first render of chat B → the diff classifies every chat B message as "new while away" until the reset effect lands. |
+| RC7 | **Cache load loses race with network refresh** | `apps/desktop/src/lib/useConversationMessages.ts:249-263` | Because state still holds chat A's messages, the cache-effect bails. Then refresh writes chat B's network result. Then the now-irrelevant `loadCachedMessages(chatB)` promise resolves and would no-op (length check still > 0 by then) — but the path is fragile and depends on timing. |
+
+**All of RC1, RC3, RC4, RC5, RC6, RC7 are fixed in one stroke by Task 3 (`key={id}` remount).** RC2 is fixed because Virtuoso unmounts with its parent and re-applies `initialTopMostItemIndex` on the fresh mount. The remaining flicker after a remount — the brief spinner before async cache hydration completes — is eliminated by Task 2 (in-memory cache, synchronous on first render).
+
+---
+
+## File Structure
+
+- **Create**: `apps/desktop/src/lib/messageMemoryCache.ts` — small module-scoped Map plus `get` / `set` / `has` API. Lets us unit-test the cache logic without rendering the hook.
+- **Create**: `apps/desktop/src/lib/messageMemoryCache.test.ts` — vitest unit tests for the cache.
+- **Modify**: `apps/desktop/src/lib/useConversationMessages.ts` — initialize `useState` from `messageMemoryCache`, sync to it on every state change.
+- **Modify**: `apps/desktop/src/App.tsx` — add `ConversationRoute` wrapper that reads `useParams` and renders `<ConversationPage key={id} />`.
+- **Modify**: `apps/desktop/src/pages/ConversationPage.tsx` — delete the now-redundant `useEffect([id])` reset block and update the `scrollPositions` doc comment.
+
+Each task below is self-contained and can be committed independently.
+
+---
+
+## Task 1: In-memory message cache helper
+
+**Files:**
+- Create: `apps/desktop/src/lib/messageMemoryCache.ts`
+- Test: `apps/desktop/src/lib/messageMemoryCache.test.ts`
+
+- [ ] **Step 1: Write the failing test**
+
+Create `apps/desktop/src/lib/messageMemoryCache.test.ts`:
+
+```ts
+import { afterEach, describe, expect, it } from 'vitest';
+import type { DecryptedMessage } from '@chat-app/shared/chat';
+
+import {
+  __resetForTests,
+  getCachedMessages,
+  hasCachedMessages,
+  setCachedMessages,
+} from './messageMemoryCache';
+
+function msg(id: string): DecryptedMessage {
+  return {
+    id,
+    conversationId: 'conv-1',
+    senderId: 'sender-1',
+    senderDeviceId: null,
+    replyToId: null,
+    editedAt: null,
+    deletedAt: null,
+    createdAt: '2026-05-17T00:00:00Z',
+    ciphertext: new Uint8Array(),
+    nonce: new Uint8Array(),
+    keyVersion: 1,
+    plaintext: 'hi ' + id,
+  };
+}
+
+describe('messageMemoryCache', () => {
+  afterEach(() => {
+    __resetForTests();
+  });
+
+  it('returns empty array when nothing is cached', () => {
+    expect(getCachedMessages('unknown')).toEqual([]);
+    expect(hasCachedMessages('unknown')).toBe(false);
+  });
+
+  it('stores and returns messages per conversation', () => {
+    setCachedMessages('a', [msg('m1'), msg('m2')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
+    expect(hasCachedMessages('a')).toBe(true);
+  });
+
+  it('isolates conversations', () => {
+    setCachedMessages('a', [msg('m1')]);
+    setCachedMessages('b', [msg('m9')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1']);
+    expect(getCachedMessages('b').map((m) => m.id)).toEqual(['m9']);
+  });
+
+  it('overwrites prior cache when set again', () => {
+    setCachedMessages('a', [msg('m1')]);
+    setCachedMessages('a', [msg('m1'), msg('m2')]);
+    expect(getCachedMessages('a').map((m) => m.id)).toEqual(['m1', 'm2']);
+  });
+
+  it('treats an explicit empty list as "cached"', () => {
+    // A conversation that genuinely has zero messages should still be
+    // flagged as cached so the hook skips the loading spinner on re-entry.
+    setCachedMessages('a', []);
+    expect(hasCachedMessages('a')).toBe(true);
+    expect(getCachedMessages('a')).toEqual([]);
+  });
+});
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `pnpm --filter @chat-app/desktop test -- messageMemoryCache`
+
+Expected: FAIL — module `./messageMemoryCache` does not exist.
+
+- [ ] **Step 3: Implement the helper**
+
+Create `apps/desktop/src/lib/messageMemoryCache.ts`:
+
+```ts
+// In-memory cache of the most-recently-rendered messages for each
+// conversation. Survives React component unmount/remount (used by
+// `useConversationMessages` to initialize state synchronously when
+// ConversationPage is remounted on chat switch). Session-scoped — lost
+// on full app reload. The SQLite cache (`messageCache.ts`) is still the
+// source of truth for cross-session persistence; this layer just shaves
+// off the round-trip-to-disk spinner flash.
+//
+// Two-tier semantics:
+//   * `hasCachedMessages(id)` returns true even for a known-empty chat
+//     so the hook can suppress the loading spinner on re-entry.
+//   * `getCachedMessages(id)` returns a defensive copy so callers can't
+//     mutate the cached array.
+
+import type { DecryptedMessage } from '@chat-app/shared/chat';
+
+const cache = new Map<string, DecryptedMessage[]>();
+
+export function getCachedMessages(conversationId: string): DecryptedMessage[] {
+  const stored = cache.get(conversationId);
+  return stored ? stored.slice() : [];
+}
+
+export function hasCachedMessages(conversationId: string): boolean {
+  return cache.has(conversationId);
+}
+
+export function setCachedMessages(
+  conversationId: string,
+  messages: DecryptedMessage[],
+): void {
+  cache.set(conversationId, messages.slice());
+}
+
+export function __resetForTests(): void {
+  cache.clear();
+}
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `pnpm --filter @chat-app/desktop test -- messageMemoryCache`
+
+Expected: PASS — all five test cases.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add apps/desktop/src/lib/messageMemoryCache.ts apps/desktop/src/lib/messageMemoryCache.test.ts
+git commit -m "feat(chat-switch): in-memory message cache helper"
+```
+
+---
+
+## Task 2: Wire the memory cache into `useConversationMessages`
+
+**Files:**
+- Modify: `apps/desktop/src/lib/useConversationMessages.ts:85` (initial state)
+- Modify: `apps/desktop/src/lib/useConversationMessages.ts:226-243` (refresh) — sync to memory cache
+- Modify: `apps/desktop/src/lib/useConversationMessages.ts:249-263` (SQLite cache effect) — skip on memory-hit, sync after hydrate
+- Modify: `apps/desktop/src/lib/useConversationMessages.ts:339, 350, 419, 433, 553` (realtime + optimistic-send paths) — keep cache in sync with state
+
+The hook keeps using `setState` everywhere — we just mirror writes into the memory cache and read from it on first render. No behavioural change for other code paths.
+
+- [ ] **Step 1: Import the helper and initialize state from cache**
+
+In `apps/desktop/src/lib/useConversationMessages.ts`, add the import near the other local-lib imports (around line 36):
+
+```ts
+import {
+  getCachedMessages,
+  hasCachedMessages,
+  setCachedMessages,
+} from './messageMemoryCache';
+```
+
+Replace the initial `useState` at line 85:
+
+```ts
+const [state, setState] = useState<State>({ messages: [], loading: true, error: null });
+```
+
+with:
+
+```ts
+// Initialize from the in-memory cache so a previously-viewed chat shows
+// content on the very first render after the parent remounts on `:id`
+// change. `loading` stays true ONLY for never-seen conversations (cache
+// miss) so the spinner doesn't flash on every chat switch.
+const [state, setState] = useState<State>(() => {
+  if (conversationId && hasCachedMessages(conversationId)) {
+    return {
+      messages: getCachedMessages(conversationId),
+      loading: false,
+      error: null,
+    };
+  }
+  return { messages: [], loading: true, error: null };
+});
+```
+
+- [ ] **Step 2: Mirror successful refreshes into the memory cache**
+
+In the `refresh` function (around line 229-235), replace:
+
+```ts
+const rows = await fetchConversationMessages(supabase, conversationId);
+const decrypted = await decryptBatch(rows);
+setState({ messages: decrypted, loading: false, error: null });
+// Persist the fresh batch to the local cache so next conversation
+// switch / app start can hydrate instantly. Fire-and-forget — cache
+// write failure is never user-visible.
+void persistMessages(conversationId, decrypted);
+```
+
+with:
+
+```ts
+const rows = await fetchConversationMessages(supabase, conversationId);
+const decrypted = await decryptBatch(rows);
+setState({ messages: decrypted, loading: false, error: null });
+setCachedMessages(conversationId, decrypted);
+// Persist the fresh batch to the local cache so next conversation
+// switch / app start can hydrate instantly. Fire-and-forget — cache
+// write failure is never user-visible.
+void persistMessages(conversationId, decrypted);
+```
+
+- [ ] **Step 3: Skip SQLite hydration on memory-cache hit, mirror cold-miss into memory**
+
+Replace the cache-hydration effect (around line 249-263):
+
+```ts
+useEffect(() => {
+  if (!conversationId) return;
+  let cancelled = false;
+  void loadCachedMessages(conversationId).then((cached) => {
+    if (cancelled || cached.length === 0) return;
+    setState((prev) => {
+      // Don't clobber a fresh server response that already landed.
+      if (prev.messages.length > 0) return prev;
+      return { messages: cached, loading: false, error: null };
+    });
+  });
+  return () => {
+    cancelled = true;
+  };
+}, [conversationId]);
+```
+
+with:
+
+```ts
+useEffect(() => {
+  if (!conversationId) return;
+  // Memory cache already populated state synchronously — skip the disk
+  // round-trip entirely. The canonical data lands shortly via refresh();
+  // the SQLite cache only matters for cold-start hydration.
+  if (hasCachedMessages(conversationId)) return;
+  let cancelled = false;
+  void loadCachedMessages(conversationId).then((cached) => {
+    if (cancelled || cached.length === 0) return;
+    setState((prev) => {
+      // Don't clobber a fresh server response that already landed.
+      if (prev.messages.length > 0) return prev;
+      setCachedMessages(conversationId, cached);
+      return { messages: cached, loading: false, error: null };
+    });
+  });
+  return () => {
+    cancelled = true;
+  };
+}, [conversationId]);
+```
+
+- [ ] **Step 4: Mirror realtime INSERT into the memory cache**
+
+In `handleInsert` (around line 339), replace:
+
+```ts
+setState((prev) => {
+  if (prev.messages.some((m) => m.id === decrypted!.id)) return prev;
+  return { ...prev, messages: [...prev.messages, decrypted!] };
+});
+```
+
+with:
+
+```ts
+setState((prev) => {
+  if (prev.messages.some((m) => m.id === decrypted!.id)) return prev;
+  const next = [...prev.messages, decrypted!];
+  if (conversationId) setCachedMessages(conversationId, next);
+  return { ...prev, messages: next };
+});
+```
+
+- [ ] **Step 5: Mirror realtime UPDATE (both partial and re-decrypt paths)**
+
+In `handleUpdate` partial-update path (around line 350-362), replace:
+
+```ts
+setState((prev) => {
+  const idx = prev.messages.findIndex((m) => m.id === partial.id);
+  if (idx === -1) return prev;
+  const existing = prev.messages[idx];
+  if (!existing) return prev;
+  const next = [...prev.messages];
+  next[idx] = {
+    ...existing,
+    editedAt: partial.editedAt,
+    deletedAt: partial.deletedAt,
+  };
+  return { ...prev, messages: next };
+});
+```
+
+with:
+
+```ts
+setState((prev) => {
+  const idx = prev.messages.findIndex((m) => m.id === partial.id);
+  if (idx === -1) return prev;
+  const existing = prev.messages[idx];
+  if (!existing) return prev;
+  const next = [...prev.messages];
+  next[idx] = {
+    ...existing,
+    editedAt: partial.editedAt,
+    deletedAt: partial.deletedAt,
+  };
+  if (conversationId) setCachedMessages(conversationId, next);
+  return { ...prev, messages: next };
+});
+```
+
+In the same function's re-decrypt path (around line 419-425), replace:
+
+```ts
+setState((prev) => {
+  const idx = prev.messages.findIndex((m) => m.id === decrypted!.id);
+  if (idx === -1) return prev;
+  const next = [...prev.messages];
+  next[idx] = decrypted!;
+  return { ...prev, messages: next };
+});
+```
+
+with:
+
+```ts
+setState((prev) => {
+  const idx = prev.messages.findIndex((m) => m.id === decrypted!.id);
+  if (idx === -1) return prev;
+  const next = [...prev.messages];
+  next[idx] = decrypted!;
+  if (conversationId) setCachedMessages(conversationId, next);
+  return { ...prev, messages: next };
+});
+```
+
+- [ ] **Step 6: Mirror realtime DELETE**
+
+Replace `handleDelete` (around line 431-438):
+
+```ts
+const handleDelete = useCallback((row: Record<string, unknown>) => {
+  const id = String(row.id);
+  setState((prev) => ({
+    ...prev,
+    messages: prev.messages.filter((m) => m.id !== id),
+  }));
+  void deleteCachedMessage(id);
+}, []);
+```
+
+with:
+
+```ts
+const handleDelete = useCallback(
+  (row: Record<string, unknown>) => {
+    const id = String(row.id);
+    setState((prev) => {
+      const next = prev.messages.filter((m) => m.id !== id);
+      if (conversationId) setCachedMessages(conversationId, next);
+      return { ...prev, messages: next };
+    });
+    void deleteCachedMessage(id);
+  },
+  [conversationId],
+);
+```
+
+- [ ] **Step 7: Mirror optimistic send (sendText)**
+
+In `sendText` (around line 553-562), replace:
+
+```ts
+setState((prev) => {
+  if (prev.messages.some((m) => m.id === msg.id)) return prev;
+  return {
+    ...prev,
+    messages: [
+      ...prev.messages,
+      { ...msg, plaintext: text } as DecryptedMessage,
+    ],
+  };
+});
+```
+
+with:
+
+```ts
+setState((prev) => {
+  if (prev.messages.some((m) => m.id === msg.id)) return prev;
+  const next = [
+    ...prev.messages,
+    { ...msg, plaintext: text } as DecryptedMessage,
+  ];
+  setCachedMessages(convId, next);
+  return { ...prev, messages: next };
+});
+```
+
+(`convId` is already a parameter of `sendText` — no extra capture needed.)
+
+- [ ] **Step 8: Run all desktop tests to verify nothing regressed**
+
+Run: `pnpm --filter @chat-app/desktop test`
+
+Expected: PASS — existing tests still green, the new `messageMemoryCache` tests still pass.
+
+- [ ] **Step 9: Commit**
+
+```bash
+git add apps/desktop/src/lib/useConversationMessages.ts
+git commit -m "feat(chat-switch): hydrate useConversationMessages from in-memory cache"
+```
+
+---
+
+## Task 3: Force fresh `ConversationPage` mount per `:id`
+
+**Files:**
+- Modify: `apps/desktop/src/App.tsx:2` (import `useParams`)
+- Modify: `apps/desktop/src/App.tsx:55-61` area (add wrapper)
+- Modify: `apps/desktop/src/App.tsx:113-120` (the `:id` route)
+
+- [ ] **Step 1: Add `useParams` to the router import**
+
+Change line 2:
+
+```ts
+import { HashRouter, Navigate, Outlet, Route, Routes } from 'react-router-dom';
+```
+
+to:
+
+```ts
+import { HashRouter, Navigate, Outlet, Route, Routes, useParams } from 'react-router-dom';
+```
+
+- [ ] **Step 2: Add the wrapper component**
+
+Below the `RouteBoundary` function (around line 61), add:
+
+```tsx
+// Forces a fresh `ConversationPage` instance per `:id` so React unmounts
+// the previous conversation entirely on switch. Without this, the same
+// component instance handles every conversation, which leaks state
+// between chats (messages, scroll position, composer drafts) for one
+// render frame and gives the "flicker" we're trying to remove.
+// `useConversationMessages` re-hydrates from `messageMemoryCache` on the
+// fresh mount so previously-visited chats still render instantly.
+function ConversationRoute() {
+  const { id } = useParams<{ id: string }>();
+  return <ConversationPage key={id ?? '__no_id__'} />;
+}
+```
+
+- [ ] **Step 3: Use the wrapper in the route definition**
+
+Replace lines 113-120:
+
+```tsx
+<Route
+  path=":id"
+  element={
+    <ErrorBoundary scope="conversation">
+      <ConversationPage />
+    </ErrorBoundary>
+  }
+/>
+```
+
+with:
+
+```tsx
+<Route
+  path=":id"
+  element={
+    <ErrorBoundary scope="conversation">
+      <ConversationRoute />
+    </ErrorBoundary>
+  }
+/>
+```
+
+- [ ] **Step 4: Typecheck**
+
+Run: `pnpm --filter @chat-app/desktop typecheck`
+
+Expected: PASS — no type errors.
+
+- [ ] **Step 5: Manual smoke test in dev**
+
+Run: `pnpm desktop:dev`
+
+In the app:
+1. Open two conversations with cached messages.
+2. Toggle between them rapidly (5+ switches).
+3. Verify: no "ghost" of the previous chat's last message ever appears, and the spinner does **not** flash on switch.
+4. Scroll chat A up by ~10 messages, switch to B, switch back to A. The Virtuoso list lands at the same scroll row, not the bottom and not at row 0.
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add apps/desktop/src/App.tsx
+git commit -m "fix(chat-switch): remount ConversationPage per conversation id"
+```
+
+---
+
+## Task 4: Drop redundant id-change reset effect & update doc comment
+
+Because the parent is remounted per id (Task 3), every state in ConversationPage is already fresh on chat switch. The manual reset effect and related comments are now misleading dead weight.
+
+**Files:**
+- Modify: `apps/desktop/src/pages/ConversationPage.tsx:97-110` — update `scrollPositions` doc comment
+- Modify: `apps/desktop/src/pages/ConversationPage.tsx:307-320` — delete the reset effect
+
+- [ ] **Step 1: Update the `scrollPositions` doc comment**
+
+Replace lines 97-110:
+
+```ts
+// Per-conversation scroll memory. Module-scoped so it survives re-mounts
+// of ConversationPage when the route param (`id`) changes — switching
+// chats unmounts/remounts the page in our router setup. Session-only
+// (lost on reload, like Discord). The `stickToBottom` flag is preserved
+// alongside the topmost-visible row index so a chat the user left at the
+// bottom keeps auto-following new messages when they return; a chat
+// scrolled up returns to roughly the same row the user was reading.
+//
+// We track the topmost-visible row index rather than a pixel `scrollTop`
+// because `react-virtuoso` virtualizes the list — the underlying scroll
+// element's pixel offset depends on dynamically-measured row heights and
+// is not stable across re-mounts. Using a row index restores the user's
+// reading position even if some rows above re-render at different heights.
+const scrollPositions = new Map<string, { topmostIndex: number; stickToBottom: boolean }>();
+```
+
+with:
+
+```ts
+// Per-conversation scroll memory. Module-scoped so it survives the
+// per-id remount of ConversationPage (see `ConversationRoute` in
+// App.tsx). Session-only (lost on reload, like Discord). The
+// `stickToBottom` flag is preserved alongside the topmost-visible row
+// index so a chat the user left at the bottom keeps auto-following new
+// messages when they return; a chat scrolled up returns to roughly the
+// same row the user was reading.
+//
+// We track the topmost-visible row index rather than a pixel `scrollTop`
+// because `react-virtuoso` virtualizes the list — the underlying scroll
+// element's pixel offset depends on dynamically-measured row heights and
+// is not stable across remounts. Using a row index restores the user's
+// reading position even if some rows above re-render at different heights.
+const scrollPositions = new Map<string, { topmostIndex: number; stickToBottom: boolean }>();
+```
+
+- [ ] **Step 2: Delete the manual reset effect**
+
+Delete lines 307-320 entirely (the effect that resets `replyTo`, `forwardTarget`, `searchOpen`, `mediaDrawerOpen`, `pollDialogOpen`, `searchQuery`, `displayCount`, `firstUnreadId`, `firstUnreadJumpDismissed`, `newMessagesWhileAway`, `previousMessageIdsRef`, `firstUnreadComputedRef`):
+
+```ts
+useEffect(() => {
+  setReplyTo(null);
+  setForwardTarget(null);
+  setSearchOpen(false);
+  setMediaDrawerOpen(false);
+  setPollDialogOpen(false);
+  setSearchQuery('');
+  setDisplayCount(150);
+  setFirstUnreadId(null);
+  setFirstUnreadJumpDismissed(false);
+  setNewMessagesWhileAway(0);
+  previousMessageIdsRef.current = new Set();
+  firstUnreadComputedRef.current = false;
+}, [id]);
+```
+
+- [ ] **Step 3: Typecheck + tests**
+
+Run in parallel:
+
+```bash
+pnpm --filter @chat-app/desktop typecheck
+pnpm --filter @chat-app/desktop test
+```
+
+Expected: both PASS.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add apps/desktop/src/pages/ConversationPage.tsx
+git commit -m "refactor(chat-switch): drop redundant id-change reset effect"
+```
+
+---
+
+## Task 5: Final QA in dev mode
+
+Verification only — no code changes, no commit.
+
+- [ ] **Step 1: Start dev**
+
+Run: `pnpm desktop:dev`
+
+- [ ] **Step 2: Confirm each fix landed**
+
+Switch repeatedly between three chats (A, B, C). All of the following must hold:
+
+| Behaviour | Pass criteria |
+|-----------|---------------|
+| Ghost messages | Never see chat A's messages under chat B's header. |
+| Spinner flash | First visit to a chat = spinner OK. Subsequent visits = no spinner. |
+| Scroll restore | Chat A scrolled up 10 rows → switch to B → back to A → lands at row 10 ±1. |
+| Composer state | Type "draft" in chat A composer → switch to B → composer is empty (drafts intentionally don't persist). |
+| Reply preview | Click reply on chat A → switch to B → no reply preview in B. |
+| Pending bubbles | Send while offline → bubble shows in correct chat → switch away and back → bubble still in same chat. |
+| Realtime updates | Send a message in chat A from another device → it lands in chat A list → switch to B → switch back to A → message is still there (verifies memory cache stays in sync with realtime inserts). |
+
+- [ ] **Step 3: If any check fails**
+
+Open `superpowers:systematic-debugging` and form a single new hypothesis per failing check. Do NOT layer fixes — return to Phase 1, gather evidence, then patch.
+
+---
+
+## Self-Review (post-write checklist)
+
+**Spec coverage**: Each RC1–RC7 is addressed:
+- RC1 (state bleed) → Task 3 (key-based remount) + Task 2 (memory cache so the fresh mount is instant).
+- RC2 (Virtuoso scroll) → Task 3 (Virtuoso unmounts with parent, `initialTopMostItemIndex` re-applied on fresh mount).
+- RC3 (scrollPositions corruption) → Task 3 (no more cross-chat render under wrong id).
+- RC4 (stale local state for one render) → Task 3 + Task 4 (cleanup).
+- RC5 (phantom scroll-to-bottom) → Task 3 (fresh ref).
+- RC6 (newMessagesWhileAway misfire) → Task 3 (fresh ref).
+- RC7 (cache vs network race) → Task 2 (deterministic init from memory cache, SQLite hydration only on cold cache miss).
+
+**Placeholders**: none — every step lists exact files, exact code, exact commands.
+
+**Type consistency**: `ConversationRoute` is the only new component; `messageMemoryCache` exports (`getCachedMessages`, `hasCachedMessages`, `setCachedMessages`, `__resetForTests`) match the test imports exactly.
+
+---
+
+## Out of scope
+
+- **Cross-fade animation between chats.** A small `view-transition` or opacity tween could further polish the swap, but the user reported jumpiness, not the absence of an animation. Tackle in a follow-up if it still feels too "snap-y" after this lands.
+- **Persisting composer drafts per chat.** Today every chat-switch loses the in-progress draft. The remount in Task 3 *preserves* that behaviour deliberately (no regression). A draft-persistence feature is a separate spec.
+- **Mobile (`apps/mobile`).** The mobile chat list uses a different virtualization stack; this plan only covers `apps/desktop`.

packages/shared/src/chat/convKeys.ts

@@ -28,7 +28,28 @@ export interface ConvKeyHandle {
 const cache = new Map<string, ConvKeyHandle>();
 const cacheKey = (convId: string, v: number) => convId + '@' + v;
 
-export function clearConvKeyCache(): void { cache.clear(); }
+// Clear the in-memory conv-key cache. Three modes:
+//   * no args     → clear everything (e.g. on logout)
+//   * convId only → clear all key-version entries for this conversation
+//   * convId + v  → clear just the specific (conv, version) entry
+//
+// Callers that observe a peer rotation or a server-side conv-keys mutation
+// MUST invalidate the affected entries so subsequent `getOrCreateConvKey` /
+// `tryGetConvKey` calls re-fetch the canonical bundle from the server
+// instead of returning a now-stale cached key.
+export function clearConvKeyCache(conversationId?: string, keyVersion?: number): void {
+  if (conversationId === undefined) {
+    cache.clear();
+    return;
+  }
+  if (keyVersion !== undefined) {
+    cache.delete(cacheKey(conversationId, keyVersion));
+    return;
+  }
+  for (const key of Array.from(cache.keys())) {
+    if (key.startsWith(conversationId + '@')) cache.delete(key);
+  }
+}
 
 async function listMemberPublicKeys(
   client: AppSupabaseClient,
@@ -110,7 +131,26 @@ export async function bootstrapConvKey(
     p_bundles: bundles,
   });
   if (error) throw error;
-  const handle = { conversationId, keyVersion, key: convKey };
+
+  // `share_conv_keys` uses `ON CONFLICT (conv, recipient_user_id, key_version)
+  // DO NOTHING`. If a concurrent peer bootstrapped first at the same version,
+  // OUR INSERTs were silently skipped server-side and the row on the server
+  // holds THEIR conv-key, not ours. Trusting the locally-generated key here
+  // would leave both clients with mutually un-decryptable bundles (each
+  // encrypting/decrypting with its own key — exactly the bug that broke
+  // conv aae12d84). Re-fetch our own bundle and unwrap to get the CANONICAL
+  // server key. Whoever wrote first wins; the loser converges.
+  const ownBundle = await fetchKeyBundle(client, conversationId, own.userId, keyVersion);
+  if (!ownBundle) {
+    throw new Error('bootstrapConvKey: own bundle missing after share_conv_keys');
+  }
+  const canonicalKey = await unwrapConvKey(
+    ownBundle.encryptedKey,
+    ownBundle.nonce,
+    ownBundle.sender.senderPublicKey,
+    own.privateKey,
+  );
+  const handle = { conversationId, keyVersion, key: canonicalKey };
   cache.set(cacheKey(conversationId, keyVersion), handle);
   return handle;
 }
@@ -125,12 +165,25 @@ export async function getOrCreateConvKey(
   if (cached) return cached;
   const bundle = await fetchKeyBundle(client, conversationId, own.userId, version);
   if (bundle) {
+    try {
       const key = await unwrapConvKey(
         bundle.encryptedKey, bundle.nonce, bundle.sender.senderPublicKey, own.privateKey,
       );
       const handle = { conversationId, keyVersion: version, key };
       cache.set(cacheKey(conversationId, version), handle);
       return handle;
+    } catch (err) {
+      // A bundle exists for us but our current private key cannot unwrap it.
+      // The most common cause is `reset_user_key`: a fresh user-key pair was
+      // generated locally while the on-server bundle is still wrapped against
+      // the previous public key. Treat this the same as "no bundle for me" —
+      // mint a fresh conv-key at version+1 wrapped to our CURRENT key. Old
+      // messages stay unreadable for us; new ones flow.
+      console.warn(
+        '[conv-key] unwrap own bundle failed at v' + version + ' — auto-rotating',
+        err,
+      );
+    }
   }
   const { count, error: cntErr } = await rawFrom(client, 'conversation_keys')
     .select('recipient_user_id', { count: 'exact', head: true })
@@ -138,12 +191,13 @@ export async function getOrCreateConvKey(
     .eq('key_version', version);
   if (cntErr) throw cntErr;
   if ((count ?? 0) > 0) {
-    // Rows exist for this version, but none for me. Either I lost the device-key
+    // Rows exist for this version, but none usable for me. Either I lost the
-    // that originally received my bundle, or my own bundle was wiped by the
+    // device-key that originally received my bundle, my own bundle was wiped
-    // 0.18.0 reset_user_key bug. Either way, the only way out is to mint a fresh
+    // by the 0.18.0 reset_user_key bug, or my key was reset and the existing
-    // conv-key at version+1 and wrap it for everyone we can. Old messages stay
+    // bundle is unwrappable (handled in the try/catch above). The only way
-    // unreadable for me; new ones flow.
+    // out is to mint a fresh conv-key at version+1 and wrap it for everyone
-    console.info('[conv-key] no bundle for me at v' + version + ' — auto-rotating');
+    // we can. Old messages stay unreadable for me; new ones flow.
+    console.info('[conv-key] no usable bundle for me at v' + version + ' — auto-rotating');
     return rotateConvKey(client, conversationId, own);
   }
   return bootstrapConvKey(client, conversationId, own, version);
@@ -248,9 +302,24 @@ export async function tryGetConvKey(
   if (cached) return cached;
   const bundle = await fetchKeyBundle(client, conversationId, ownUserId, keyVersion);
   if (!bundle) return null;
-  const key = await unwrapConvKey(
+  let key: Uint8Array;
+  try {
+    key = await unwrapConvKey(
       bundle.encryptedKey, bundle.nonce, bundle.sender.senderPublicKey, ownPrivateKey,
     );
+  } catch (err) {
+    // Bundle exists but the current private key doesn't unwrap it (typically
+    // after `reset_user_key`). Return null so the caller treats the message
+    // as un-decryptable instead of throwing and killing the whole batch.
+    // The conversation will be auto-rotated to a fresh key on the next send
+    // or chat open via `getOrCreateConvKey`'s own recovery path.
+    console.warn(
+      '[conv-key] tryGetConvKey unwrap failed at v' + keyVersion +
+        ' (conv=' + conversationId.slice(0, 8) + ') — marking as un-decryptable',
+      err,
+    );
+    return null;
+  }
   const handle = { conversationId, keyVersion, key };
   cache.set(cacheKey(conversationId, keyVersion), handle);
   return handle;