Refactor AegisGym to compliant structure, fix metadata 500 error, and improve grader logic.

fix: implement sigmoid normalization in grader and neutral 0.5 fallback to natively comply with strict OpenEnv score bounds

fix inference fallback

Fix: Add mandatory main() function and project scripts for Meta validator

Fix: Add root redirector and package exports for HF Space startup

Fix: Emergency restoration of core logic and models

Refactor: Final structural sync for multi-mode deployment with uv.lock