fix(desktop): address code-review findings on the desktop wave

- fileEntries: a single unreadable file/dir in a dropped folder no longer aborts
  the whole traversal (try/catch per entry, skip failures) — was discarding ALL
  dropped files (incl. the flat-file path) + an unhandled rejection; also add
  .catch in both useFileDrop consumers.
- RoomInput: mirror a localStorage-restored draft into the draft atom so the
  P5-57 indicator reflects a persisted draft after a page reload, not only on
  same-session room re-entry.
- useTauriThumbbar: swallow toggleMicrophone()/hangup() rejections (parity with
  SMTC) — avoids an unhandled rejection when clicked mid-teardown.
- App/DesktopChrome: keep wrapper element types stable across the chrome toggle
  (display:contents when off) so flipping it no longer remounts RouterProvider.
- settings: normalizeComposerToolbarOrder also appends missing keys from the
  canonical key set (safety net if a new button is absent from the default order).

Gates: tsc/eslint/prettier clean, build OK, 559 tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/hooks/useTauriThumbbar.ts

@@ -31,13 +31,14 @@ export function useTauriThumbbar(): void {
     if (!callEmbed) return;
     if (action === 'mute') {
       // toggleMicrophone flips the mic; `microphone === false` means muted.
-      callEmbed.control.toggleMicrophone();
+      // Async transport send — swallow rejection (widget mid-teardown), as SMTC does.
+      callEmbed.control.toggleMicrophone().catch(() => undefined);
     } else if (action === 'deafen') {
       // toggleSound flips local audio; `sound === false` means deafened. It also
       // mutes the mic while deafened, matching the in-app Deafen control.
       callEmbed.control.toggleSound();
     } else if (action === 'end') {
-      callEmbed.hangup();
+      callEmbed.hangup().catch(() => undefined);
     }
   });
 }