feat: punkt 5 (monitoring) — system dashboard backend+frontend, admin-only, auto-refresh 30s, alerting via notifications

frontend/src/api/systemDashboard.ts

@@ -0,0 +1,104 @@
+/**
+ * System Dashboard API hooks — admin-only system monitoring.
+ */
+
+import { useQuery } from '@tanstack/react-query';
+import { apiGet } from './client';
+
+// ── Types matching backend responses ──
+
+export interface SystemDashboardData {
+  overall_status: string;
+  timestamp: string;
+  database: {
+    status: string;
+    connections?: number;
+    table_count?: number;
+    db_size_bytes?: number;
+    db_size_human?: string;
+    error?: string;
+  };
+  redis: {
+    status: string;
+    connections?: number;
+    used_memory?: number;
+    used_memory_human?: string;
+    peak_memory_human?: string;
+    uptime_seconds?: number;
+    error?: string;
+  };
+  worker: {
+    status: string;
+    queue_length?: number;
+    active_workers?: number;
+    error?: string;
+  };
+  api: {
+    total_requests?: number;
+    error_count?: number;
+    error_rate?: number;
+    avg_response_time_ms?: number;
+    error?: string;
+  };
+  plugins: {
+    total_discovered?: number;
+    active_plugins?: Array<{
+      name: string;
+      version: string;
+      is_core: boolean;
+    }>;
+    error_count?: number;
+    errors?: string[];
+    error?: string;
+  };
+  storage: {
+    status: string;
+    path?: string;
+    disk_total_bytes?: number;
+    disk_used_bytes?: number;
+    disk_free_bytes?: number;
+    disk_usage_percent?: number;
+    file_count?: number;
+    error?: string;
+  };
+  llm: {
+    total_tokens: number;
+    estimated_cost: number;
+    last_24h_tokens: number;
+    last_24h_cost: number;
+  };
+}
+
+export interface SystemAlert {
+  severity: 'critical' | 'warning';
+  type: string;
+  message: string;
+}
+
+export interface SystemAlertsData {
+  alerts: SystemAlert[];
+  alert_count: number;
+  timestamp: string;
+}
+
+// ── Hooks ──
+
+const REFRESH_INTERVAL = 30 * 1000; // 30 seconds
+
+export function useSystemDashboard() {
+  return useQuery({
+    queryKey: ['system-dashboard'],
+    queryFn: () => apiGet<SystemDashboardData>('/system/dashboard'),
+    refetchInterval: REFRESH_INTERVAL,
+    staleTime: REFRESH_INTERVAL,
+  });
+}
+
+export function useSystemAlerts() {
+  return useQuery({
+    queryKey: ['system-alerts'],
+    queryFn: () => apiGet<SystemAlertsData>('/system/alerts'),
+    refetchInterval: REFRESH_INTERVAL,
+    staleTime: REFRESH_INTERVAL,
+  });
+}