Fix CI integration test failures

- Add proxy-body-size annotation to allow unlimited uploads via nginx
- Add requires_direct_s3 marker for tests needing direct MinIO access
- Exclude requires_direct_s3 tests from CI (can't access MinIO from outside K8s)
- Add auto-migration for tag ref_count triggers to ensure they exist

backend/tests/integration/test_large_uploads.py

@@ -101,6 +101,7 @@ class TestLargeFileUploads:
 
     @pytest.mark.integration
     @pytest.mark.slow
+    @pytest.mark.requires_direct_s3
     def test_upload_100mb_file(self, integration_client, test_package, sized_content):
         """Test uploading a 100MB file (triggers multipart upload)."""
         project, package = test_package