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_upload_download_api.py

@@ -158,6 +158,7 @@ class TestUploadBasics:
         assert artifact["size"] == len(content)
 
     @pytest.mark.integration
+    @pytest.mark.requires_direct_s3
     def test_upload_creates_object_in_s3(self, integration_client, test_package):
         """Test upload creates object in S3 storage."""
         project, package = test_package
@@ -635,6 +636,7 @@ class TestUploadFailureCleanup:
     """Tests for cleanup when uploads fail."""
 
     @pytest.mark.integration
+    @pytest.mark.requires_direct_s3
     def test_upload_failure_invalid_project_no_orphaned_s3(
         self, integration_client, unique_test_id
     ):
@@ -657,6 +659,7 @@ class TestUploadFailureCleanup:
         )
 
     @pytest.mark.integration
+    @pytest.mark.requires_direct_s3
     def test_upload_failure_invalid_package_no_orphaned_s3(
         self, integration_client, test_project, unique_test_id
     ):
@@ -704,6 +707,7 @@ class TestS3StorageVerification:
     """Tests to verify S3 storage behavior."""
 
     @pytest.mark.integration
+    @pytest.mark.requires_direct_s3
     def test_s3_single_object_after_duplicates(
         self, integration_client, test_package, unique_test_id
     ):
@@ -759,6 +763,7 @@ class TestSecurityPathTraversal:
     """
 
     @pytest.mark.integration
+    @pytest.mark.requires_direct_s3
     def test_path_traversal_in_filename_stored_safely(
         self, integration_client, test_package
     ):