Changelog and versioning

• R-CHG-01: Each release unit keeps a discoverable changelog in its declared format · oss-changelog
• R-CHG-02: Semantic versions reflect changes to the declared public API · oss-changelog
• R-CHG-03: Every release unit uses one version across its tag, manifests, and changelog · oss-changelog
• R-CHG-04: Forge release notes derive from the changelog without contradicting it · oss-changelog
• R-CHG-05: A public API is deprecated in a release before it is removed · oss-changelog