fix(apps): always attempt K8s cleanup on delete, cluster service fixes

- Delete endpoint no longer requires clusterId && latestImageTag
- Clusters: getDefault fallback logic, reassign apps on delete
- Unit tests for cluster default/delete logic

backend/src/applications/applications.controller.ts

@@ -62,7 +62,7 @@ export class ApplicationsController {
   }
 
   @Post(':id/db-upload')
-  @ApiOperation({ summary: 'Upload and restore a SQL dump into the application database' })
+  @ApiOperation({ summary: 'Upload a SQL dump file for later restore during deployment' })
   @ApiConsumes('multipart/form-data')
   @UseInterceptors(FileInterceptor('file', {
     limits: { fileSize: 500 * 1024 * 1024 }, // 500MB for DB dumps
@@ -84,12 +84,13 @@ export class ApplicationsController {
     }
 
     this.logger.log(`DB dump upload for ${app.name} — ${(file.size / 1024).toFixed(1)} KB`);
-    const result = await this.kubernetesService.restoreDatabaseDump(app, file.buffer);
+
+    // Save to disk (restore happens after deploy when namespace exists)
+    await this.applicationsService.uploadDbDump(id, isStaff ? app.userId : req.user.id, file);
 
     return {
-      success: result.success,
-      message: result.success ? 'Database restored successfully' : 'Database restore failed',
-      logs: result.logs,
+      success: true,
+      message: 'Database dump uploaded. It will be restored automatically after deployment.',
     };
   }
 
@@ -225,12 +226,10 @@ export class ApplicationsController {
     // 1. Get the app first
     const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);
 
-    // 2. Delete K8s resources (deployment, service, ingress, db, secrets)
+    // 2. Delete K8s resources (deployment, service, ingress, db, secrets, PVCs)
     try {
-      if (app.clusterId && app.latestImageTag) {
-        await this.kubernetesService.deleteApplication(app);
-        this.logger.log(`Deleted K8s resources for ${app.name}`);
-      }
+      await this.kubernetesService.deleteApplication(app);
+      this.logger.log(`Deleted K8s resources for ${app.name}`);
     } catch (e: any) {
       this.logger.warn(`K8s cleanup failed for ${app.name}: ${e.message}`);
     }