fix: openenv.yaml tasks graders + strict score bounds

fix: add safe_reward() clamp at every reward return point

Add normalize_reward(); enforce strict (0,1) on all paths

Update grading logic to strict (0,1) ratio fallback

fix: OpenEnv multi-mode compliance — add main() entrypoint and uv.lock

Production-ready: add server/app.py with fallback-safe /reset, fix Dockerfile, add HF metadata, add task JSON files

Initial commit