Login end-to-end en Next.js: iron-session + auth SRP6 + página i18n

- lib/session.ts: sesión cifrada httpOnly con iron-session (SESSION_SECRET en
  .env.local). SessionData {bnetId, bnetEmail, username, accountId}.
- lib/auth.ts: authenticate(email,password) verifica contra battlenet_accounts con
  bnetVerify (SRP6 v2); getGameAccounts(bnetId). Resiliente si acore no está.
- app/api/auth/login/route.ts: POST -> autentica, fija sesión, resuelve cuentas de
  juego (1 -> auto; 0/varias -> needsSelection). Devuelve JSON.
- app/[locale]/login: página SSR + LoginForm (cliente, next-intl, router i18n).
  Textos en messages/*.json (namespace Login).
- tsconfig target ES2020 (literales BigInt de bnet.ts).

Validado end-to-end: con una cuenta creada por bnet.py (como haría AzerothCore),
el login TS la verifica OK y emite la cookie de sesión; password incorrecta ->
invalidCredentials; sin campos -> missingFields. Página en ES y EN.

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

web-next/messages/en.json

@@ -15,5 +15,20 @@
     "noNews": "There are no news available at the moment.",
     "link": "Link",
     "here": "here"
+  },
+  "Login": {
+    "title": "Sign in to Nova WoW",
+    "email": "Email",
+    "password": "Password",
+    "submit": "Sign in",
+    "connecting": "Signing in…",
+    "success": "Signed in successfully. Redirecting…",
+    "invalidCredentials": "Incorrect email or password",
+    "missingFields": "Please fill in all fields.",
+    "invalidRequest": "Invalid request.",
+    "genericError": "Something went wrong. Please try again later.",
+    "forgot": "I forgot my password/username",
+    "newHere": "New to the community? You can create an account",
+    "createAccount": "here"
   }
 }