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/state/settings.ts

@@ -137,12 +137,22 @@ export const normalizeComposerToolbarOrder = (
       result.push(key);
     }
   });
+  // Append missing keys in their canonical default position…
   DEFAULT_COMPOSER_TOOLBAR_ORDER.forEach((key) => {
     if (!seen.has(key)) {
       seen.add(key);
       result.push(key);
     }
   });
+  // …then any known key not covered by the default order (safety net so a new
+  // button added to COMPOSER_TOOLBAR_BUTTON_KEYS but forgotten in the default
+  // order can still render/reorder rather than being permanently dropped).
+  COMPOSER_TOOLBAR_BUTTON_KEYS.forEach((key) => {
+    if (!seen.has(key)) {
+      seen.add(key);
+      result.push(key);
+    }
+  });
 
   return result;
 };