Document Boatstack product configuration

[bigboateng]

Summary

• replace the changelog-only README block with a shorter repository-policy entry point
• add a complete, value-first Boatstack configuration guide and correct the canonical schema
• project the guide into the public distribution
• add an implementation-derived supervisory test that fails when serialized configuration fields and either documentation surface drift
• add the required release-note fragment

Why

Boatstack exposed multiple repository policy settings, but the public README highlighted only maintain_changelog and the canonical schema omitted newer fields. Maintainers had to reverse-engineer the example configuration and implementation to understand supported policy.

The new two-slice documentation keeps the README compact while making the linked guide authoritative. The supervisory contract derives the public configuration surface from Go JSON tags, so adding, removing, or renaming a field without updating both documentation surfaces fails CI.

Impact

Maintainers can choose configuration from desired delivery outcomes, see every supported field and default, and receive an automated failure if implementation and documentation diverge later. Runtime configuration behavior is unchanged.

Validation

• go test ./...
• python3 -m unittest labs/12-product-engineering-loop/tests/test_product_loop.py
• python3 labs/12-product-engineering-loop/scripts/release_notes.py validate --root labs/12-product-engineering-loop/boatstack-distribution/release-notes
• git diff --check
• all JSON examples parse and the full example passes the real configuration validator
• projected documentation links resolve and the public README remains shorter than before