feat: add Stars payment confirmation and admin validation

- Show confirmation dialog before redirecting to Telegram for Stars
  payment (native popup in Mini App, confirm in browser)
- Warn admin when saving wheel config with Stars enabled but
  Telegram Stars payment method is disabled globally
- Add translation keys: confirmStarsTitle, confirmStarsPayment,
  starsNotEnabledGlobally (ru, en, zh, fa)

src/locales/en.json

@@ -714,6 +714,8 @@
     "starsPaymentFailed": "Payment failed. Please try again.",
     "starsPaymentRedirected": "Telegram will open for payment. Refresh the page after payment.",
     "starsNotAvailable": "Star payments are currently unavailable. Contact support.",
+    "confirmStarsTitle": "Star payment",
+    "confirmStarsPayment": "You will be redirected to Telegram to pay for one wheel spin. Continue?",
     "youWon": "You won",
     "noPrize": "No luck this time...",
     "noHistory": "No spin history yet",
@@ -978,6 +980,7 @@
         "promocodes": "Promocodes",
         "promoPrefix": "Promo code prefix"
       },
+      "starsNotEnabledGlobally": "Star payments are not enabled in Payment Methods. Enable \"Telegram Stars\" in the Payment Methods section.",
       "prizes": {
         "addPrize": "Add Prize",
         "editPrize": "Edit Prize",