UI: tab-bar navigation — drop the hamburger

Replace Menu.svelte (hamburger) everywhere with tab-bar navigation:
- Settings hub (SettingsHub) from the lobby ⚙️ tab: Settings/Profile/
  Friends/About as in-place tabs, back → lobby; the lobby ⚙️ badge counts
  incoming friend requests (invitations keep their own lobby section).
- Comms hub (CommsHub) from the move-history 💬: Chat/Dictionary tabs,
  back → game; Dictionary only while the game is active.
- Game menu items relocate into the open history: 🏁 leave / 📤 export in
  the header, 🤝 add-friend per opponent card, 💬 comms; unread chat is
  badged on the score bar + the 💬.
- TapConfirm (tap → fading ✅ → tap) replaces the Skip/Hint press-and-hold
  popovers and drives the add-friend confirm.
- Fix the move-history "jump": the slid board is inert and the stage can't
  scroll, so a swipe up genuinely closes the history.

Remove Menu.svelte + HoldConfirm.svelte. Docs: UI_DESIGN, FUNCTIONAL(+ru),
PRERELEASE. UI check/unit/build/bundle/e2e (Chromium+WebKit) all green.

ui/src/lib/app.svelte.ts

@@ -49,9 +49,9 @@ export const app = $state<{
   /** Draw grid lines between board cells; off (default) is a gapless checkerboard. */
   boardLines: boolean;
   localeLocked: boolean;
-  /** Pending incoming friend requests + invitations, for the lobby badge. */
+  /** Pending incoming friend requests, for the lobby ⚙️ badge and the Settings Friends tab. */
   notifications: number;
-  /** Unread chat-message count per game id, for the in-game menu/hamburger badge. */
+  /** Unread chat-message count per game id, for the in-game score-bar and 💬 badges. */
   chatUnread: Record<string, number>;
 }>({
   ready: false,
@@ -139,9 +139,12 @@ function openStream(): void {
       reportOnline(); // a delivered event proves the gateway is reachable
       app.lastEvent = e;
       if (e.kind === 'chat_message' && e.message.senderId !== app.session?.userId) {
-        // While the player is on that game's chat screen, neither toast nor bump the unread.
-        const onChat = router.route.name === 'gameChat' && router.route.params.id === e.message.gameId;
-        if (!onChat) {
+        // While the player is in that game's comms hub (chat or dictionary tab), neither
+        // toast nor bump the unread — the chat is a tap away and reloads on open.
+        const inComms =
+          (router.route.name === 'gameChat' || router.route.name === 'gameCheck') &&
+          router.route.params.id === e.message.gameId;
+        if (!inComms) {
           if (e.message.kind !== 'nudge') {
             const gid = e.message.gameId;
             app.chatUnread = { ...app.chatUnread, [gid]: (app.chatUnread[gid] ?? 0) + 1 };
@@ -186,9 +189,10 @@ function scheduleReconnect(): void {
 }
 
 /**
- * refreshNotifications recomputes the lobby badge count (incoming friend requests
- * plus open invitations). Authoritative poll, complementing the live 'notify' push.
- * Guests have no social surfaces, so it is a no-op for them.
+ * refreshNotifications recomputes the badge count (incoming friend requests).
+ * Authoritative poll, complementing the live 'notify' push. Game invitations have
+ * their own lobby section, so they are not counted here. Guests have no social
+ * surfaces, so it is a no-op for them.
  */
 export async function refreshNotifications(): Promise<void> {
   if (!app.session || app.profile?.isGuest) {
@@ -196,11 +200,7 @@ export async function refreshNotifications(): Promise<void> {
     return;
   }
   try {
-    const [incoming, invitations] = await Promise.all([
-      gateway.friendsIncoming(),
-      gateway.invitationsList(),
-    ]);
-    app.notifications = incoming.length + invitations.length;
+    app.notifications = (await gateway.friendsIncoming()).length;
   } catch {
     // Best-effort; leave the previous count on a transient failure.
   }
@@ -260,7 +260,7 @@ function syncTelegramChrome(): void {
 /**
  * syncTelegramSafeArea mirrors Telegram's content-safe-area top inset (the height its native
  * nav overlays the viewport in fullscreen) into the --tg-content-top CSS var and toggles a
- * `tg-fullscreen` class, so the header can drop below the nav and lift the menu into its
+ * `tg-fullscreen` class, so the header can drop below the nav and centre the title in its
  * band. Called on launch and on Telegram's safe-area / fullscreen change events.
  */
 function syncTelegramSafeArea(): void {