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/jobs/cleanup_jobs.py

@@ -0,0 +1,102 @@
+"""
+Cleanup jobs registered with APScheduler.
+
+Jobs:
+  - cleanup_old_logs:     Delete log entries older than 7 days, daily at 03:00
+  - cleanup_old_metrics:  Delete metrics older than 1 day, every 6 hours
+  - cleanup_old_events:   Delete events older than 30 days, weekly on Sunday
+"""
+from __future__ import annotations
+
+import logging
+
+from apscheduler.triggers.cron import CronTrigger
+from apscheduler.triggers.interval import IntervalTrigger
+
+from core.jobs.scheduler import get_scheduler
+from database import get_thread_db
+from core.dal.log_repository import LogRepository
+from core.dal.metrics_repository import MetricsRepository
+from core.dal.event_repository import EventRepository
+
+logger = logging.getLogger(__name__)
+
+_LOG_RETENTION_DAYS = 7
+_METRICS_RETENTION_DAYS = 1
+_EVENT_RETENTION_DAYS = 30
+
+
+def register_cleanup_jobs() -> None:
+    """Register all cleanup jobs with the scheduler. Call at startup."""
+    sched = get_scheduler()
+
+    sched.add_job(
+        func=_cleanup_old_logs,
+        trigger=CronTrigger(hour=3, minute=0),
+        id="cleanup_old_logs",
+        name="Clean up old log entries",
+        replace_existing=True,
+    )
+
+    sched.add_job(
+        func=_cleanup_old_metrics,
+        trigger=IntervalTrigger(hours=6),
+        id="cleanup_old_metrics",
+        name="Clean up old metrics",
+        replace_existing=True,
+    )
+
+    sched.add_job(
+        func=_cleanup_old_events,
+        trigger=CronTrigger(day_of_week="sun", hour=4, minute=0),
+        id="cleanup_old_events",
+        name="Clean up old events",
+        replace_existing=True,
+    )
+
+    logger.info("Cleanup jobs registered")
+
+
+def _cleanup_old_logs() -> None:
+    logger.info("Running log cleanup (retention=%d days)", _LOG_RETENTION_DAYS)
+    try:
+        db = get_thread_db()
+        try:
+            log_repo = LogRepository(db)
+            log_repo.cleanup_old(retention_days=_LOG_RETENTION_DAYS)
+            db.commit()
+        finally:
+            db.close()
+        logger.info("Log cleanup complete")
+    except Exception as exc:
+        logger.error("Log cleanup failed: %s", exc, exc_info=True)
+
+
+def _cleanup_old_metrics() -> None:
+    logger.info("Running metrics cleanup (retention=%d days)", _METRICS_RETENTION_DAYS)
+    try:
+        db = get_thread_db()
+        try:
+            metrics_repo = MetricsRepository(db)
+            metrics_repo.cleanup_old(retention_days=_METRICS_RETENTION_DAYS)
+            db.commit()
+        finally:
+            db.close()
+        logger.info("Metrics cleanup complete")
+    except Exception as exc:
+        logger.error("Metrics cleanup failed: %s", exc, exc_info=True)
+
+
+def _cleanup_old_events() -> None:
+    logger.info("Running event cleanup (retention=%d days)", _EVENT_RETENTION_DAYS)
+    try:
+        db = get_thread_db()
+        try:
+            event_repo = EventRepository(db)
+            event_repo.cleanup_old(retention_days=_EVENT_RETENTION_DAYS)
+            db.commit()
+        finally:
+            db.close()
+        logger.info("Event cleanup complete")
+    except Exception as exc:
+        logger.error("Event cleanup failed: %s", exc, exc_info=True)