fix: allow cross-origin team photos on Render for Vercel frontend

Helmet CORP blocked /uploads images from eene-dashboard.vercel.app.
Also add photo file upload to db:push-remote and db:push-photos script.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/app.ts

@@ -8,7 +8,12 @@ import routes from './routes';
 
 const app = express();
 
-app.use(helmet());
+// Vercel 프론트에서 Render /uploads 이미지를 img로 불러올 수 있도록 cross-origin 허용
+app.use(
+  helmet({
+    crossOriginResourcePolicy: { policy: 'cross-origin' },
+  }),
+);
 const allowedOrigins = [
   'http://localhost:3000',
   'http://localhost:5173',