feat(desktop): Tier A desktop features — web side (P5-46/36/44/43/49/47/55/57)

Web half of the desktop feature wave. A shared bridge (`hooks/useTauri.ts`:
invokeTauri/isTauri/useTauriEvent) backs per-feature hooks that no-op in the
browser and drive the native Tauri commands (compiled in cinny-desktop):

- P5-46 useTauriCallPower — hold system awake while a call is active.
- P5-36 useTauriJumpList — Windows jump list of recent rooms → matrix: deep links.
- P5-44 useTauriThumbbar — taskbar Mute/Deafen/End; events toggle mic/sound/hangup.
- P5-43 useTauriSmtc — SMTC call state + button events.
- P5-49 useTauriNetwork — react to native network-change → mx.retryImmediately().
- P5-47 window chrome — opt-in `customWindowChromeAtom` + TDS `TitleBar`; DesktopChrome
  wrapper in App.tsx (zero layout impact when off) + a desktop-only settings toggle.
- P5-55 composer toolbar drag-reorder (settings order[] + pragmatic-drag-and-drop).
- P5-57 DraftIndicator — subtle "draft saved" cue in the composer.

Client-scoped hooks mount via TauriDesktopFeatures in ClientNonUIFeatures; window
chrome mounts at App level. Gates: tsc/eslint/prettier clean, build OK, 556 tests.

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

src/app/state/customWindowChrome.ts

@@ -0,0 +1,22 @@
+import {
+  atomWithLocalStorage,
+  getLocalStorageItem,
+  setLocalStorageItem,
+} from './utils/atomWithLocalStorage';
+
+const CUSTOM_WINDOW_CHROME = 'customWindowChrome';
+
+/**
+ * P5-47 — TDS Custom Window Chrome opt-in flag (default `false`).
+ *
+ * Standalone, `localStorage`-backed boolean atom kept separate from
+ * `state/settings.ts` on purpose. When `true` (and running inside Tauri) the app
+ * strips the native window frame and renders its own `<TitleBar/>`; when `false`
+ * the native OS frame is used. The feature is runtime-reversible, so flipping
+ * this atom is all it takes to switch back and forth.
+ */
+export const customWindowChromeAtom = atomWithLocalStorage<boolean>(
+  CUSTOM_WINDOW_CHROME,
+  (key) => getLocalStorageItem<boolean>(key, false),
+  (key, value) => setLocalStorageItem(key, value),
+);

src/app/state/settings.ts

@@ -60,6 +60,39 @@ export enum MessageLayout {
   Bubble = 2,
 }
 
+/**
+ * Keys of the toggleable composer toolbar buttons. Also used as the identity
+ * of each button when persisting/restoring a custom drag-and-drop order.
+ */
+export const COMPOSER_TOOLBAR_BUTTON_KEYS = [
+  'showFormat',
+  'showEmoji',
+  'showSticker',
+  'showGif',
+  'showLocation',
+  'showPoll',
+  'showVoice',
+  'showSchedule',
+] as const;
+
+export type ComposerToolbarButtonKey = (typeof COMPOSER_TOOLBAR_BUTTON_KEYS)[number];
+
+/**
+ * The fixed order the composer toolbar rendered before reordering existed.
+ * Used as the fallback for users without a saved order, and to append any
+ * new/unknown button keys, so existing users see no change.
+ */
+export const DEFAULT_COMPOSER_TOOLBAR_ORDER: ComposerToolbarButtonKey[] = [
+  'showFormat',
+  'showSticker',
+  'showEmoji',
+  'showGif',
+  'showLocation',
+  'showPoll',
+  'showVoice',
+  'showSchedule',
+];
+
 export interface ComposerToolbarSettings {
   showFormat: boolean;
   showEmoji: boolean;
@@ -69,6 +102,7 @@ export interface ComposerToolbarSettings {
   showPoll: boolean;
   showVoice: boolean;
   showSchedule: boolean;
+  order: ComposerToolbarButtonKey[];
 }
 
 export const DEFAULT_COMPOSER_TOOLBAR: ComposerToolbarSettings = {
@@ -80,6 +114,37 @@ export const DEFAULT_COMPOSER_TOOLBAR: ComposerToolbarSettings = {
   showPoll: true,
   showVoice: true,
   showSchedule: true,
+  order: DEFAULT_COMPOSER_TOOLBAR_ORDER,
+};
+
+/**
+ * Returns a complete, de-duplicated composer toolbar order:
+ * - drops unknown/duplicate keys from the saved order
+ * - appends any missing keys (new buttons or existing users with no saved
+ *   order) at the end in their canonical default position
+ * so a button can never disappear from the toolbar.
+ */
+export const normalizeComposerToolbarOrder = (
+  order: ComposerToolbarButtonKey[] | undefined,
+): ComposerToolbarButtonKey[] => {
+  const known = new Set<ComposerToolbarButtonKey>(COMPOSER_TOOLBAR_BUTTON_KEYS);
+  const seen = new Set<ComposerToolbarButtonKey>();
+  const result: ComposerToolbarButtonKey[] = [];
+
+  (order ?? []).forEach((key) => {
+    if (known.has(key) && !seen.has(key)) {
+      seen.add(key);
+      result.push(key);
+    }
+  });
+  DEFAULT_COMPOSER_TOOLBAR_ORDER.forEach((key) => {
+    if (!seen.has(key)) {
+      seen.add(key);
+      result.push(key);
+    }
+  });
+
+  return result;
 };
 
 export interface Settings {
@@ -318,6 +383,7 @@ export const getSettings = (): Settings => {
       composerToolbarButtons: {
         ...DEFAULT_COMPOSER_TOOLBAR,
         ...(saved.composerToolbarButtons ?? {}),
+        order: normalizeComposerToolbarOrder(saved.composerToolbarButtons?.order),
       },
     };
   } catch {