feat: add backup monitoring TypeScript types

frontend/src/types/backups.ts

@@ -0,0 +1,40 @@
+export interface BackupJob {
+    id: string;
+    name: string;
+    source: string | null;
+    target: string | null;
+    schedule_interval_seconds: number | null;
+    created_at: number;
+}
+
+export interface BackupRun {
+    id: string;
+    job_id: string;
+    started_at: number;
+    ended_at: number | null;
+    status: "success" | "failure" | "in_progress";
+    bytes_transferred: number | null;
+    duration_ms: number | null;
+    error_message: string | null;
+    details_json: Record<string, unknown> | null;
+    created_at: number;
+}
+
+export interface BackupAlert {
+    id: string;
+    job_id: string;
+    run_id: string | null;
+    alert_type: "missed_schedule" | "failed_status" | "anomaly_size" | "anomaly_duration";
+    severity: "warning" | "critical";
+    message: string;
+    acknowledged: boolean;
+    resolved_at: number | null;
+    created_at: number;
+}
+
+export interface BackupDashboardSummary {
+    total_jobs: number;
+    success_rate_24h: number;
+    active_alerts: number;
+    last_failed_at: number | null;
+}