feat(backup): Add backup scheduling system with GFS retention, API and UI integration

ts/types.ts

@@ -323,6 +323,24 @@ export interface ICliArgs {
 // Backup types
 export type TBackupRestoreMode = 'restore' | 'import' | 'clone';
 
+// Retention policy for GFS (Grandfather-Father-Son) time-window based retention
+export interface IRetentionPolicy {
+  hourly: number;   // 0 = disabled, else keep up to N backups from last 24h
+  daily: number;    // Keep 1 backup per day for last N days
+  weekly: number;   // Keep 1 backup per week for last N weeks
+  monthly: number;  // Keep 1 backup per month for last N months
+}
+
+// Default retention presets
+export const RETENTION_PRESETS = {
+  standard: { hourly: 0, daily: 7, weekly: 4, monthly: 12 },
+  frequent: { hourly: 24, daily: 7, weekly: 4, monthly: 12 },
+  minimal: { hourly: 0, daily: 3, weekly: 2, monthly: 6 },
+  longterm: { hourly: 0, daily: 14, weekly: 8, monthly: 24 },
+} as const;
+
+export type TRetentionPreset = keyof typeof RETENTION_PRESETS | 'custom';
+
 export interface IBackup {
   id?: number;
   serviceId: number;
@@ -333,6 +351,8 @@ export interface IBackup {
   includesImage: boolean;
   platformResources: TPlatformServiceType[];  // Which platform types were backed up
   checksum: string;
+  // Scheduled backup fields
+  scheduleId?: number;  // Links backup to its schedule for retention
 }
 
 export interface IBackupManifest {
@@ -384,3 +404,43 @@ export interface IRestoreResult {
   platformResourcesRestored: number;
   warnings: string[];
 }
+
+// Backup scheduling types (GFS retention scheme)
+export type TBackupScheduleScope = 'all' | 'pattern' | 'service';
+
+export interface IBackupSchedule {
+  id?: number;
+  scopeType: TBackupScheduleScope;
+  scopePattern?: string;        // Glob pattern for 'pattern' scope type
+  serviceId?: number;           // Only for 'service' scope type
+  serviceName?: string;         // Only for 'service' scope type
+  cronExpression: string;
+  retention: IRetentionPolicy;  // Per-tier retention counts
+  enabled: boolean;
+  lastRunAt: number | null;
+  nextRunAt: number | null;
+  lastStatus: 'success' | 'failed' | null;
+  lastError: string | null;
+  createdAt: number;
+  updatedAt: number;
+}
+
+export interface IBackupScheduleCreate {
+  scopeType: TBackupScheduleScope;
+  scopePattern?: string;        // Required for 'pattern' scope type
+  serviceName?: string;         // Required for 'service' scope type
+  cronExpression: string;
+  retention: IRetentionPolicy;
+  enabled?: boolean;
+}
+
+export interface IBackupScheduleUpdate {
+  cronExpression?: string;
+  retention?: IRetentionPolicy;
+  enabled?: boolean;
+}
+
+// Backup creation options (for scheduled backups)
+export interface IBackupCreateOptions {
+  scheduleId?: number;
+}