Security: Passwort-Minimum, Rate Limits, Headers, Passwort-vergessen, email_verified

- Passwort-Minimum 8 Zeichen bei Register + Reset
- Rate Limit auf /resend-verification (3/h) und /forgot-password (3/h)
- Security-Headers: X-Frame-Options, X-Content-Type-Options, Referrer-Policy etc.
- email_verified in get_current_user SELECT ergänzt
- Forum: create_thread + create_post erfordern email_verified
- POST /auth/forgot-password + /auth/reset-password (2h-Token, via support@)
- DB-Migration: password_reset_token + password_reset_expires
- Frontend: Passwort-vergessen-Modal im Login, Reset-Formular mit Passphrase-Generator
- SW by-v576, APP_VER 553

backend/database.py

@@ -565,6 +565,9 @@ def _migrate(conn_factory):
         ("users", "is_partner",          "INTEGER NOT NULL DEFAULT 0"),
         ("users", "founder_number",      "INTEGER"),
         ("users", "is_founder_pending",  "INTEGER NOT NULL DEFAULT 0"),
+        # Passwort-Zurücksetzen
+        ("users", "password_reset_token",   "TEXT"),
+        ("users", "password_reset_expires", "TEXT"),
     ]
     with conn_factory() as conn:
         for table, column, col_type in migrations: