Ensure API parallel runs emit config metadata for aggregation

[TommrraraSnow]

Summary

• write .parallel_config.json for API parallel sessions so downstream aggregation sees enabled flags and feature configs
• relax parallel data helpers to treat enable/enabled interchangeably and fall back to func
• add an API test that exercises the writer and confirms aggregation succeeds with both key names

Testing

• pytest tests/api/test_session_op.py (skipped: fastapi missing in test environment)

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https://chatgpt.com/codex/tasks/task_e_68da025ed364832d8d010d996a887b15

[github-actions]

🤖 Hi @TommrraraSnow, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.