Show live online-players count on the home screen

- OnlineService.getOnlineCount(); mock random-walks a believable number,
  SignalrService reads GET /api/stats/online (server tracks hub connections)
- Home screen badge with pulsing dot, polls every 8s, localized digits

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

src/lib/i18n.tsx

@@ -27,6 +27,7 @@ const fa: Dict = {
   "home.start": "بزن بریم",
   "home.howTo": "آموزش بازی",
   "home.lang": "English",
+  "home.onlineCount": "{n} نفر آنلاین",
 
   "seat.you": "شما",
   "team.us": "ما",
@@ -249,6 +250,7 @@ const en: Dict = {
   "home.start": "Let's go",
   "home.howTo": "How to play",
   "home.lang": "فارسی",
+  "home.onlineCount": "{n} players online",
 
   "seat.you": "You",
   "team.us": "Us",