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

frontend/src/lib/api.ts

@@ -20,8 +20,12 @@ apiClient.interceptors.response.use(
   (response) => response,
   (error) => {
     if (error.response?.status === 401) {
-      localStorage.removeItem("languard_token");
-      window.location.href = "/login";
+      const url = error.config?.url ?? "";
+      // Don't redirect on auth endpoints — let the calling component handle the error
+      if (!url.startsWith("/api/auth/")) {
+        localStorage.removeItem("languard_token");
+        window.location.href = "/login";
+      }
     }
     return Promise.reject(error);
   },

frontend/src/lib/logger.ts

@@ -0,0 +1,54 @@
+/**
+ * Lightweight logger for the frontend.
+ *
+ * In development: logs to console with level-appropriate methods.
+ * In production: can be swapped for an error reporting service (Sentry, etc.)
+ * by replacing the transport in logger.ts.
+ */
+
+type LogLevel = "debug" | "info" | "warn" | "error";
+
+const LOG_LEVELS: Record<LogLevel, number> = {
+  debug: 0,
+  info: 1,
+  warn: 2,
+  error: 3,
+};
+
+const currentLevel: LogLevel =
+  (import.meta.env.VITE_LOG_LEVEL as LogLevel) ??
+  (import.meta.env.DEV ? "debug" : "warn");
+
+function shouldLog(level: LogLevel): boolean {
+  return LOG_LEVELS[level] >= LOG_LEVELS[currentLevel];
+}
+
+function formatMessage(level: LogLevel, context: string, message: string): string {
+  return `[${level.toUpperCase()}] [${context}] ${message}`;
+}
+
+export const logger = {
+  debug(context: string, message: string, ...args: unknown[]) {
+    if (shouldLog("debug")) {
+      console.debug(formatMessage("debug", context, message), ...args);
+    }
+  },
+
+  info(context: string, message: string, ...args: unknown[]) {
+    if (shouldLog("info")) {
+      console.info(formatMessage("info", context, message), ...args);
+    }
+  },
+
+  warn(context: string, message: string, ...args: unknown[]) {
+    if (shouldLog("warn")) {
+      console.warn(formatMessage("warn", context, message), ...args);
+    }
+  },
+
+  error(context: string, message: string, ...args: unknown[]) {
+    if (shouldLog("error")) {
+      console.error(formatMessage("error", context, message), ...args);
+    }
+  },
+};