Add Kobo as a first-class metadata source so books can keep Kobo IDs across fetch, edit, import, scoring, and file-write flows. Provide the Python cloudscraper setup needed for production fetches while keeping local setup explicit.
Closes#247
Validate BO-<issue>-<slug> branch names and lint PR titles and commit headers in CI and release workflows.
Require GitHub closing-keyword issue references and verify referenced issues exist. Align contributing, release, commit, testing, and policy docs with the enforced behavior and tone.