feat(lifecycle): add billing lifecycle with auto-suspend/delete

- New AppLifecycleService with cron-based scanner (60s interval)
- State machine: ACTIVE → SUSPENDED → PENDING_DELETION → DELETED
- Auto-renew hourly plans from wallet
- Admin-configurable grace periods via PlatformSettings table
- New LifecycleController (GET/PATCH /lifecycle/settings)
- PlatformSetting entity for runtime admin config
- BillingService: calculateCostForApp, deductWallet
- Application entity: planId, billingCycle, lifecycleStatus, planExpiresAt
- New enums: AppLifecycleStatus, BillingCycle

backend/src/applications/entities/application.entity.ts

@@ -8,7 +8,7 @@ import {
   OneToMany,
   JoinColumn,
 } from 'typeorm';
-import { AppRuntime, DatabaseType } from '../../common/enums';
+import { AppRuntime, DatabaseType, BillingCycle, AppLifecycleStatus } from '../../common/enums';
 import { User } from '../../users/entities/user.entity';
 import { Deployment } from '../../deployments/entities/deployment.entity';
 
@@ -59,6 +59,9 @@ export class Application {
   @Column({ nullable: true })
   codePath: string; // Path to uploaded zip
 
+  @Column({ nullable: true })
+  dbDumpPath: string; // Path to uploaded SQL dump file
+
   @Column({ type: 'jsonb', nullable: true })
   envVars: Record<string, string>;
 
@@ -105,6 +108,25 @@ export class Application {
   @Column({ nullable: true })
   subdomain: string; // <subdomain>.apps.cloudhost.local
 
+  // ── Billing & Lifecycle ─────────────────────────────
+  @Column({ nullable: true })
+  planId: string; // FK to ServicePlan
+
+  @Column({ type: 'enum', enum: BillingCycle, nullable: true })
+  billingCycle: BillingCycle; // The cycle this app was purchased under
+
+  @Column({ type: 'enum', enum: AppLifecycleStatus, default: AppLifecycleStatus.ACTIVE })
+  lifecycleStatus: AppLifecycleStatus;
+
+  @Column({ type: 'timestamptz', nullable: true })
+  planExpiresAt: Date; // When the current billing period ends
+
+  @Column({ type: 'timestamptz', nullable: true })
+  suspendedAt: Date; // When the app was suspended (pods scaled to 0)
+
+  @Column({ type: 'timestamptz', nullable: true })
+  scheduledDeletionAt: Date; // When the app will be permanently deleted
+
   @CreateDateColumn()
   createdAt: Date;