fix: pure backend deployment - removed conflicting SDK metadata and simplified API

fix: force Docker SDK and resolve HTML/JSON conflict for validator

fix: exact Phase 1 compliance API for OpenEnv validator

fix: bulletproof JSON compliance for OpenEnv validator

fix: full compliance with Phase 1 OpenEnv validator schema

fix: exact ResetResponse schema alignment for Phase 1 validator

fix: expose OpenEnv endpoints on port 7860 to satisfy hackathon validator

Add root route for HF Space homepage

Fix HF Space runtime by adding persistent FastAPI server