fix: replace Rust CI with Python CI workflow

tests/test_integration.py

@@ -1,4 +1,4 @@
-"""Integration tests for the complete workflow."""
+"""Integration tests for JSON to OpenAPI Generator."""
 import pytest
 import json
 import yaml
@@ -159,6 +159,7 @@ class TestIntegration:
         ])
 
         assert result.exit_code == 0
+        assert "Generated combined spec" in result.output or "combined.yaml" in result.output
 
     def test_spec_validity(self, runner, user_schema_file, tmp_path):
         """Test that generated spec is valid OpenAPI 3.0.3."""