feat: file variety, user status, DND gate, drag-drop, mentions, link preview, emoji picker, soundboard, ringtone

Attachments
- Video: native <video controls>, decrypted blob, metadata preload
- PDF: collapsible <object> viewer with download + preview toggle
- Generic: file card with lazy decrypt, mime-to-extension map
- MessageBubble dispatch: audio/image/video/pdf/generic by mime
- Composer accept widened from image/* to any; AttachmentPreview renders
  non-images as file cards

User status
- usePeerPresence returns { state, statusMessage } and tracks both fields
  via realtime updates
- ConversationHeader subtitle shows custom status_message when peer is
  online/idle/dnd (with message set); falls back to localized presence
  label; always "Offline" when state === 'offline'
- UserBar: status_message input in dropdown (max 128 chars, save on
  blur/Enter), subtitle uses same precedence as peer view
- AuthContext: auto-flip offline → online on session mount; best-effort
  offline on beforeunload/pagehide; respects explicit idle/dnd/invisible
- i18n: presence.status_placeholder (DE + EN)

DND
- CallUI: incoming ring suppressed when own presence === 'dnd' (outgoing
  rings stay audible — user-initiated)
- CallContext: presenceRef mirrors profile.presenceState, incoming-call
  and missed-call OS notifications skipped under DND
- ConversationsContext already gated message tone + notify

Drag/drop + paste
- Page-root drag handlers feed ingestFiles; overlay shown while dragging
- Textarea onPaste extracts clipboard image items

@mentions in groups
- MentionAutocomplete: keyboard-driven dropdown, arrow/enter/tab/esc
- Composer onChange parses trailing @token, auto-open
- renderBodyWithMentions highlights @username tokens in bubbles

Link previews
- Migration 20260421000003_link_previews.sql (cache table, auth read,
  service-role write via edge function)
- Edge function og-preview: POST {url}, fetches HTML (6s timeout, 1MB
  cap), regex-parses OG/twitter/description, upserts cache
- useLinkPreview hook with in-memory cache + inflight dedup
- LinkPreviewCard rendered from first URL in message body

Emoji picker
- Built-in curated set (~250 emojis) across five categories
- Search by keyword/emoji char/category, recent list persisted in
  localStorage
- Trigger button next to + and voice buttons in composer

Soundboard + ringtone + mic pipeline
- Pulled in (user-authored) SoundboardManagerDialog/Panel/Settings,
  RingtoneSettings, mic pipeline + hotkeys + storage modules
- AuthContext imports updateOwnProfile for presence auto-flip

Fixes
- AttachmentAudio min-width so bubbles don't collapse to 0px on peer
  side
- Focus flicker: visibility/online wake refresh throttled to 30s,
  focus listener dropped, loading flag only on first fetch

apps/desktop/src/components/AttachmentGeneric.tsx

@@ -0,0 +1,127 @@
+import { type AttachmentHandle, downloadAndDecryptAttachment } from '@chat-app/shared/chat';
+import { useState } from 'react';
+
+import { supabase } from '../lib/supabase';
+import { AlertIcon, SpinnerIcon } from './icons';
+
+interface Props {
+  handle: AttachmentHandle;
+}
+
+// Catch-all card for attachments without a richer renderer (zip, docx,
+// txt, etc). Decrypt is deferred to first download click — these can be
+// large and there's no inline preview to justify auto-fetching them.
+export function AttachmentGeneric({ handle }: Props) {
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const download = async () => {
+    if (busy) return;
+    setBusy(true);
+    setError(null);
+    try {
+      const blob = await downloadAndDecryptAttachment({ client: supabase, handle });
+      const url = URL.createObjectURL(blob);
+      const a = document.createElement('a');
+      a.href = url;
+      a.download = filenameFor(handle);
+      document.body.appendChild(a);
+      a.click();
+      document.body.removeChild(a);
+      // Defer revoke so Safari has a chance to start the download.
+      setTimeout(() => URL.revokeObjectURL(url), 60_000);
+    } catch (err: unknown) {
+      setError(err instanceof Error ? err.message : 'download failed');
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <div className="mt-2 inline-flex w-[280px] items-center gap-2.5 rounded-lg border border-line bg-surface-2 p-2.5">
+      <span className="flex h-9 w-9 shrink-0 items-center justify-center rounded-md bg-accent/10 text-accent">
+        <FileGlyph />
+      </span>
+      <div className="min-w-0 flex-1">
+        <p className="truncate text-xs font-semibold text-fg">
+          {prettyMime(handle.mimeType)}
+        </p>
+        <p className="truncate text-[10px] text-fg-muted">
+          {formatSize(handle.sizeBytes)}
+        </p>
+        {error && (
+          <p className="mt-0.5 inline-flex items-center gap-1 text-[10px] text-rose-500">
+            <AlertIcon className="h-3 w-3" />
+            <span>{error}</span>
+          </p>
+        )}
+      </div>
+      <button
+        type="button"
+        onClick={() => void download()}
+        disabled={busy}
+        aria-label="Download"
+        title="Download"
+        className="flex h-8 w-8 shrink-0 cursor-pointer items-center justify-center rounded-md border border-line bg-surface-3 text-fg transition hover:brightness-95 disabled:opacity-60"
+      >
+        {busy ? <SpinnerIcon className="h-4 w-4" /> : <DownloadGlyph />}
+      </button>
+    </div>
+  );
+}
+
+function FileGlyph() {
+  return (
+    <svg viewBox="0 0 16 16" width="16" height="16" fill="currentColor" aria-hidden="true">
+      <path d="M3 2a1 1 0 011-1h6l3 3v10a1 1 0 01-1 1H4a1 1 0 01-1-1V2zm7 0v3h3l-3-3z" />
+    </svg>
+  );
+}
+
+function DownloadGlyph() {
+  return (
+    <svg viewBox="0 0 16 16" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="1.6" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
+      <path d="M8 2v8M4 7l4 4 4-4M3 13h10" />
+    </svg>
+  );
+}
+
+function filenameFor(handle: AttachmentHandle): string {
+  const ext = extFor(handle.mimeType);
+  return 'attachment-' + handle.id.slice(0, 8) + (ext ? '.' + ext : '');
+}
+
+function extFor(mime: string): string | null {
+  const map: Record<string, string> = {
+    'application/zip': 'zip',
+    'application/x-zip-compressed': 'zip',
+    'application/x-7z-compressed': '7z',
+    'application/x-tar': 'tar',
+    'application/gzip': 'gz',
+    'application/json': 'json',
+    'application/xml': 'xml',
+    'text/plain': 'txt',
+    'text/markdown': 'md',
+    'text/csv': 'csv',
+    'application/msword': 'doc',
+    'application/vnd.openxmlformats-officedocument.wordprocessingml.document': 'docx',
+    'application/vnd.ms-excel': 'xls',
+    'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet': 'xlsx',
+    'application/vnd.ms-powerpoint': 'ppt',
+    'application/vnd.openxmlformats-officedocument.presentationml.presentation': 'pptx',
+  };
+  return map[mime] ?? null;
+}
+
+function prettyMime(mime: string): string {
+  const ext = extFor(mime);
+  if (ext) return ext.toUpperCase() + '-Datei';
+  if (mime.startsWith('text/')) return 'Textdatei';
+  return mime || 'Datei';
+}
+
+function formatSize(bytes: number): string {
+  if (bytes < 1024) return bytes + ' B';
+  if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(0) + ' KB';
+  return (bytes / 1024 / 1024).toFixed(1) + ' MB';
+}