chemthermo-change-loop

Use when implementing or reviewing changes in this Chemical-Thermodynamics repository. Apply the repo contract by reading .agents/brain/brain.md first, preserving SI-unit and public-API invariants, shipping thin vertical slices with a runnable golden path, running CI-equivalent quality gates (ruff format, ruff format --check, ruff check, pyright, pytest), verifying editable and non-editable install smoke checks, and updating ADR/brain docs when architecture or public API changes.