deploy: sync staged DataForge Space

fix: add HTTP POST /reset, /step endpoints with openenv protocol wrapping - Fallback returns {observation: {...}} matching openenv format - Step accepts {action: {...}} (openenv protocol) and flat fields - Dockerfile copies client.py, inference.py, REWARD_DESIGN.md - Dockerfile --extra server ensures fastapi/uvicorn install - uv.lock synced with pyproject.toml

ULTRAPLAN: compliance fixes, grader diagnostics, stochastic mode, new corruptions

fix: add root Dockerfile for HuggingFace Spaces deployment