UNO home: mode cards + bottom nav bar

Rebuild HomeScreen to UNO's home layout: top bar (avatar+coins) + 3 big glossy
3D mode cards in the center (Online[gold,live-count badge] / vs-Computer[teal] /
Private Room[violet]) + a bottom icon nav bar (NavRail bottom variant, drops the
redundant home item). Speed toggle + language sit in a slim controls row. Online
card shows live player count; room card creates a private room then enters it.
New menu.room/menu.roomDesc i18n.

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

src/lib/i18n.tsx

@@ -109,6 +109,8 @@ const fa: Dict = {
   "menu.online": "بازی آنلاین",
   "menu.onlineDesc": "با دوستان یا بازیکن‌های واقعی",
   "nav.home": "خانه",
+  "menu.room": "اتاق دوستان",
+  "menu.roomDesc": "بازی خصوصی با دوستان",
   "menu.profile": "پروفایل",
   "menu.friends": "دوستان",
   "menu.leaderboard": "جدول امتیازات",
@@ -452,6 +454,8 @@ const en: Dict = {
   "menu.online": "Play Online",
   "menu.onlineDesc": "With friends or real players",
   "nav.home": "Home",
+  "menu.room": "Private room",
+  "menu.roomDesc": "Play privately with friends",
   "menu.profile": "Profile",
   "menu.friends": "Friends",
   "menu.leaderboard": "Leaderboard",