feat: dynamic database storage size with PVC expansion

- Add dbStorageSize column to Application entity (default: 1Gi)
- Add dbStorageSize to CreateApplicationDto, frontend types
- Use dynamic storage size in K8s deployDatabase instead of hardcoded 5Gi
- Deploy page: storage size selector with +/- buttons (min 1GB, max 100GB)
- Auto-suggest storage based on DB dump file size (3x dump size, min 1GB)
- Show DB storage in Review step
- App detail: Database Storage section with expand button
- GET /applications/:id/db-storage — read current PVC size from K8s
- PATCH /applications/:id/db-storage — expand PVC (only increase, no shrink)
- PVC resize uses JSON patch on K8s API

backend/src/applications/applications.controller.ts

@@ -93,6 +93,48 @@ export class ApplicationsController {
     };
   }
 
+  @Get(':id/db-storage')
+  @ApiOperation({ summary: 'Get current database PVC storage size' })
+  async getDbStorage(@Param('id') id: string, @Request() req: any) {
+    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
+    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);
+
+    if (app.databaseType === DatabaseType.NONE) {
+      throw new BadRequestException('This application does not have a database configured');
+    }
+
+    const currentSize = await this.kubernetesService.getDatabasePvcSize(app);
+    return { currentSize, savedSize: app.dbStorageSize || '1Gi' };
+  }
+
+  @Patch(':id/db-storage')
+  @ApiOperation({ summary: 'Resize (expand) database PVC storage' })
+  async resizeDbStorage(
+    @Param('id') id: string,
+    @Request() req: any,
+    @Body() body: { size: string },
+  ) {
+    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
+    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);
+
+    if (app.databaseType === DatabaseType.NONE) {
+      throw new BadRequestException('This application does not have a database configured');
+    }
+
+    if (!body.size || !/^\d+Gi$/.test(body.size)) {
+      throw new BadRequestException('Size must be in format like "1Gi", "5Gi", "10Gi"');
+    }
+
+    const result = await this.kubernetesService.resizeDatabasePvc(app, body.size);
+
+    if (result.success) {
+      // Update the saved size in the DB
+      await this.applicationsService.update(id, app.userId, { dbStorageSize: body.size } as any);
+    }
+
+    return result;
+  }
+
   @Get()
   @ApiOperation({ summary: 'List my applications' })
   async findAll(@Request() req: any) {