feat: implement full backend + frontend server detail, settings, and create server pages

Backend:
- Complete FastAPI backend with 42+ REST endpoints (auth, servers, config,
  players, bans, missions, mods, games, system)
- Game adapter architecture with Arma 3 as first-class adapter
- WebSocket real-time events for status, metrics, logs, players
- Background thread system (process monitor, metrics, log tail, RCon poller)
- Fernet encryption for sensitive config fields at rest
- JWT auth with admin/viewer roles, bcrypt password hashing
- SQLite with WAL mode, parameterized queries, migration system
- APScheduler cleanup jobs for logs, metrics, events

Frontend:
- Server Detail page with 7 tabs (overview, config, players, bans,
  missions, mods, logs)
- Settings page with password change and admin user management
- Create Server wizard (4-step; known bug: silent validation failure)
- New hooks: useServerDetail, useAuth, useGames
- New components: ServerHeader, ConfigEditor, PlayerTable, BanTable,
  MissionList, ModList, LogViewer, PasswordChange, UserManager
- WebSocket onEvent callback for real-time log accumulation
- 120 unit tests passing (Vitest + React Testing Library)

Docs:
- Added .gitignore, CLAUDE.md, README.md
- Updated FRONTEND.md, ARCHITECTURE.md with current implementation state
- Added .env.example for backend configuration

Known issues:
- Create Server form: "Next" buttons don't validate before advancing,
  causing silent submit failure when fields are invalid
- Config sub-tabs need UX redesign for non-technical users

backend/core/auth/utils.py

@@ -0,0 +1,48 @@
+"""JWT creation/validation and password hashing."""
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timedelta, timezone
+
+import bcrypt
+from jose import JWTError, jwt
+
+logger = logging.getLogger(__name__)
+
+
+def hash_password(password: str) -> str:
+    """Hash a password using bcrypt. Returns UTF-8 encoded hash string."""
+    password_bytes = password.encode("utf-8")
+    salt = bcrypt.gensalt()
+    hashed = bcrypt.hashpw(password_bytes, salt)
+    return hashed.decode("utf-8")
+
+
+def verify_password(plain: str, hashed: str) -> bool:
+    """Verify a plain password against a bcrypt hash."""
+    try:
+        return bcrypt.checkpw(plain.encode("utf-8"), hashed.encode("utf-8"))
+    except Exception as exc:
+        logger.warning("Password verification failed: %s", exc)
+        return False
+
+
+def create_access_token(user_id: int, username: str, role: str) -> str:
+    from config import settings
+    expire = datetime.now(timezone.utc) + timedelta(hours=settings.jwt_expire_hours)
+    payload = {
+        "sub": str(user_id),
+        "username": username,
+        "role": role,
+        "exp": expire,
+    }
+    return jwt.encode(payload, settings.secret_key, algorithm="HS256")
+
+
+def decode_access_token(token: str) -> dict:
+    """
+    Decode and validate JWT. Returns payload dict.
+    Raises JWTError on invalid/expired token.
+    """
+    from config import settings
+    return jwt.decode(token, settings.secret_key, algorithms=["HS256"])