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/utils/fileEntries.ts

@@ -77,16 +77,28 @@ export const filesFromEntries = async (
   const walk = async (entry: FileSystemEntry, prefix: string): Promise<void> => {
     if (files.length >= maxFiles) return;
 
+    // A single unreadable file/directory (moved between drop and read, a
+    // permissions/lock error, an OS special file) must NOT abort the whole
+    // traversal — skip it and keep collecting the rest.
     if (entry.isFile) {
-      const file = await fileFromFileEntry(entry as FileSystemFileEntry);
-      if (files.length >= maxFiles) return;
-      files.push(prefix ? renameFile(file, `${prefix}${file.name}`) : file);
+      try {
+        const file = await fileFromFileEntry(entry as FileSystemFileEntry);
+        if (files.length >= maxFiles) return;
+        files.push(prefix ? renameFile(file, `${prefix}${file.name}`) : file);
+      } catch {
+        /* skip unreadable file */
+      }
       return;
     }
 
     if (entry.isDirectory) {
-      const reader = (entry as FileSystemDirectoryEntry).createReader();
-      const childEntries = await readAllDirectoryEntries(reader);
+      let childEntries: FileSystemEntry[] = [];
+      try {
+        const reader = (entry as FileSystemDirectoryEntry).createReader();
+        childEntries = await readAllDirectoryEntries(reader);
+      } catch {
+        return; /* skip unreadable directory */
+      }
       const childPrefix = `${prefix}${entry.name}/`;
       for (const child of childEntries) {
         if (files.length >= maxFiles) break;