Fix OpenEnv package: swap squatter openenv for openenv-core>=0.2.1, update PROJECT.md API sections and rubrics imports to match real Meta-PyTorch framework

Pre-Phase-7 cleanup: migrate models.py to turn-budget fields, add episode_seed helper for deterministic-per-UUID sampling

Models fix: add state field to ShutdownObservation for rubric access per PROJECT.md Section 14

Phase 5: Audit classifier and rubric stack per PROJECT.md Sections 9 and 14

Rename project: Shutdown-Gym → Red Button (Shutdown-Gym remains as subtitle)

Phase 1: Initial scaffold, Claude Code workspace, repo structure per PROJECT.md Section 5