Auth: email/Google "coming soon"; mobile polish pass on the table

- AuthScreen: phone+OTP is the only active method; email & Google shown as
  disabled "coming soon" buttons (until SMTP/Gmail are configured)
- GameTable responsive: compact scoreboard, smaller seat avatars, and
  turn-indicator/timer positions tuned for small screens

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

src/lib/i18n.tsx

@@ -177,6 +177,7 @@ const fa: Dict = {
   "auth.toggleSignup": "حساب ندارید؟ ثبت‌نام کنید",
   "auth.toggleSignin": "حساب دارید؟ وارد شوید",
   "auth.invalidCode": "کد نادرست است",
+  "auth.otherSoon": "سایر روش‌های ورود به‌زودی فعال می‌شوند",
 
   "reward.title": "پاداش بازی",
   "reward.rating": "امتیاز رتبه‌ای",
@@ -403,6 +404,7 @@ const en: Dict = {
   "auth.toggleSignup": "No account? Sign up",
   "auth.toggleSignin": "Have an account? Sign in",
   "auth.invalidCode": "Invalid code",
+  "auth.otherSoon": "Other sign-in methods coming soon",
 
   "reward.title": "Match rewards",
   "reward.rating": "Rating",