Servicios de personaje de pago (Stripe): patrón + rename

- lib/stripe.ts: createCheckoutSession (crea sesión Stripe + StripeLog en
  home_stripelog, success_url con {CHECKOUT_SESSION_ID}), isSessionPaid,
  claimPaidCheckout (verifica pagado + no entregado, marca fulfilled -> evita
  re-entregas; port de require_paid_stripe).
- lib/prices.ts: precios desde home_*price (rename/customize/race/faction/level).
- components/PaidServiceForm.tsx: selector + botón de pago -> redirige a la URL de
  Checkout de Stripe (session.url, sin stripe.js).
- Rename: route /api/character/rename/checkout (guard + valida personaje + crea
  checkout), página /rename (PaidServiceForm) y /rename/success (verifica pago y
  ejecuta SOAP .char rename, i18n). STRIPE_* + NEXT_PUBLIC_STRIPE_PUBLIC_KEY en
  .env.local. Namespace Rename.

Verificado: checkout sin sesión 401, /rename redirige a login, /rename/success con
session_id inválido no entrega el servicio (muestra error). Patrón para los demás
servicios de pago (cambiar precio + comando SOAP).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-next/messages/en.json

@@ -135,5 +135,14 @@
     "cooldown": "You can only do this once every 12 hours.",
     "soapError": "Server communication error. Please try again later.",
     "genericError": "Something went wrong. Please try again later."
+  },
+  "Rename": {
+    "title": "Rename character",
+    "pay": "Rename for {price} €",
+    "successTitle": "Rename character",
+    "success": "Character {name} has been flagged for rename. The change will apply on next login.",
+    "error": "The operation could not be completed. If you were charged, contact support.",
+    "invalidCharacter": "Select a valid character.",
+    "stripeError": "Could not start the payment. Please try again later."
   }
 }