Repository: CatOpt-Play (prototype)

Architecture
- Language: Python 3.8+
- Layout: src/ package layout (src/idea36_catopt_play_category)
- Core components:
  - contracts: pydantic models for LocalProblem, SharedVariables, DualVariables, PlanDelta, PrivacyBudget, AuditLog
  - solver: an ADMM-lite consensus solver (prototype)

Tech stack
- Python with pydantic for data contracts
- pytest for tests
- setuptools/pyproject for packaging

Testing & Commands
- Run tests: `pytest`
- Build package: `python3 -m build`
- Full automation: `bash test.sh` (installs build+pytest in the environment, installs package editable, runs tests, then builds)

Rules for AI agents and contributors
- Make minimal, well-scoped edits. Prefer small changes.
- Follow src/ layout and put package code under `src/idea36_catopt_play_category`.
- Add tests for new behaviour. CI expects `pytest` to pass.
- Do not create READY_TO_PUBLISH unless the full original spec is implemented and tests pass.