Economy: free vs paid games + buy-coins page; friends remove confirmation

- Coins only matter for ranked: free games (vs computer / private friend rooms)
  cost nothing; random ranked requires an entry (stake), gated by balance →
  routes to buy-coins when short
- Buy Coins page (CoinPack/getCoinPacks/buyCoins; mock credits now, real
  Zarinpal/IDPay TODO); TopBar coins → buy; lobby create-room is Free
- Friends: removed instant red ✕ delete; UserMinus → inline confirm before remove

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

src/lib/i18n.tsx

@@ -89,6 +89,20 @@ const fa: Dict = {
   "common.copy": "کپی",
   "common.copied": "کپی شد",
   "common.free": "رایگان",
+  "common.yes": "بله",
+  "common.no": "خیر",
+
+  "buy.title": "خرید سکه",
+  "buy.note": "پرداخت امن — درگاه پرداخت ایرانی به‌زودی اضافه می‌شود",
+  "buy.toman": "تومان",
+  "buy.bonus": "هدیه",
+  "buy.popular": "محبوب",
+  "buy.best": "بهترین",
+
+  "lobby.entry": "ورودی",
+  "lobby.free": "رایگان",
+  "lobby.needCoins": "سکه کافی نیست — شارژ کنید",
+  "friends.removeQ": "این دوست حذف شود؟",
 
   "chat.title": "گفتگو",
   "chat.placeholder": "پیام بنویسید…",
@@ -316,6 +330,20 @@ const en: Dict = {
   "common.copy": "Copy",
   "common.copied": "Copied",
   "common.free": "Free",
+  "common.yes": "Yes",
+  "common.no": "No",
+
+  "buy.title": "Buy Coins",
+  "buy.note": "Secure payment — Iranian gateway coming soon",
+  "buy.toman": "Toman",
+  "buy.bonus": "bonus",
+  "buy.popular": "Popular",
+  "buy.best": "Best value",
+
+  "lobby.entry": "Entry",
+  "lobby.free": "Free",
+  "lobby.needCoins": "Not enough coins — top up",
+  "friends.removeQ": "Remove this friend?",
 
   "chat.title": "Chat",
   "chat.placeholder": "Type a message…",