CLAUDE.md@eval/multistage_v3/parcelpost/start git:20261028.1d17525A

Immutable. This exact content never changes and is served at /api/v1/blob/767b6cb383b77d66.

# Project rules

1. Keep `docs/reference.md` current whenever behaviour changes.
2. Add a `CHANGELOG.md` entry for every change.
3. Every bug fix carries a test.
4. Never edit `src/parcelpost/_generated.py`.