feat: add snapshot/rollback system with download capability

- Add AppSnapshot entity with type (pre_deploy/manual), status tracking, and file paths
- Add SnapshotsService with create, capture, rollback, prune (max 10), and download logic
- Add SnapshotsController with REST endpoints for CRUD, rollback, and file downloads
- Add K8s methods: exportDatabaseDump, archiveWpContent, restoreWpContent
- Auto-create pre-deploy snapshots before each deployment for rollback safety
- Support downloading current live state (source, wp-content, database) without snapshots
- Add snapshot management UI in app detail page with create, rollback, download, delete
- Wire circular dependencies with forwardRef between Deployments and Snapshots modules

backend/src/deployments/deployments.service.ts

@@ -6,6 +6,7 @@ import { ApplicationsService } from '../applications/applications.service';
 import { KubernetesService } from '../kubernetes/kubernetes.service';
 import { BuildService } from '../build/build.service';
 import { DeploymentStatus } from '../common/enums';
+import { SnapshotsService } from '../snapshots/snapshots.service';
 
 @Injectable()
 export class DeploymentsService {
@@ -18,11 +19,22 @@ export class DeploymentsService {
     private applicationsService: ApplicationsService,
     private kubernetesService: KubernetesService,
     private buildService: BuildService,
+    @Inject(forwardRef(() => SnapshotsService))
+    private snapshotsService: SnapshotsService,
   ) {}
 
   async triggerDeployment(applicationId: string, userId: string): Promise<Deployment> {
     const app = await this.applicationsService.findOne(applicationId, userId);
 
+    // Auto-snapshot before deploying (capture current state for rollback)
+    try {
+      const version = `v${Date.now()}`;
+      await this.snapshotsService.createPreDeploySnapshot(app.id, userId, version);
+      this.logger.log(`Pre-deploy snapshot created for ${app.name}`);
+    } catch (e: any) {
+      this.logger.warn(`Pre-deploy snapshot failed for ${app.name}: ${e.message} — continuing deploy`);
+    }
+
     // Create deployment record
     const deployment = this.deploymentsRepository.create({
       applicationId: app.id,
@@ -173,6 +185,15 @@ export class DeploymentsService {
       throw new NotFoundException('No source code available. Upload code or set a git URL first.');
     }
 
+    // Auto-snapshot before redeploy
+    try {
+      const version = `v${Date.now()}`;
+      await this.snapshotsService.createPreDeploySnapshot(app.id, userId, version);
+      this.logger.log(`Pre-redeploy snapshot created for ${app.name}`);
+    } catch (e: any) {
+      this.logger.warn(`Pre-redeploy snapshot failed for ${app.name}: ${e.message} — continuing`);
+    }
+
     // Create new deployment record
     const deployment = this.deploymentsRepository.create({
       applicationId: app.id,