fix: remove all nested duplicate folders

sync: hf-space is now the single source of truth

fix: Gradio mount, verifier stage3, poc_history clear, real notebook

fix: STAGE_FILES points stages 2-3 to actual app files + update reward_curve (LFS) + results table

feat: GRPO training, fixed curriculum stages 2+3, AST verifier, leaderboard UI, openenv schema

fix: requirements, remove stub openenv, clean pycache, fix models

fix: correct import names + full 3-phase step logic

Fix Observation import in server.py

teammate: models + judge v3-fixed

fix: stub models+judge so Space boots — teammate will override

initial deploy — jairaj files, teammate files pending