cleanup comments and readme

fix: grader variance + match sample inference.py format

chore: added hf space openenv tag

chore: remove AI comments, separate tasks by difficulty, and sync README

Restored HF config block

Removed HuggingFace YAML metadata from README

Stylistic markdown de-aiing

Swapped sterile README for hackathon swagger

Added HF Space config

Final Hackathon Submission