Generate per-deployment release notes from receipt chains #71

Outcome

Generate a plain-language release note for every completed deployment receipt and link it to the exact evidence chain.

Current behavior

The forge changelog makes pushes legible, and #33 plans recent deployment history. A push is not a deployment, and the product does not yet publish a deployment-scoped explanation that connects issues, commits, qualification, release, and environment.

Source: docs/episode-triage.md, episodes 272 and the receipt station.

Contract

• Trigger from an immutable completed deployment receipt, not from a branch push.
• Summarize the user-visible changes associated with the deployed commit range.
• Link issues, commits, qualification receipts, release receipts, deployment receipts, and permitted traces.
• Apply transparency tiers independently to every linked artifact.
• Represent empty, rollback, partial, failed, and superseded deployments explicitly.
• Keep generated wording reviewable and record its source revision and generator identity.

Acceptance criteria

• Every successful production deployment has one idempotent release-note record.
• The note names the deployed revision and environment and never implies that an undeployed push shipped.
• A rollback produces a separate note linked to the original deployment.
• Private issue titles, traces, and repositories do not leak through summaries or link metadata.
• The web page and API return the same ordered release history.

Verification

Test commit-range resolution, idempotency, privacy, rollback, partial deployment, and generated-copy review. Exercise one staging deployment and run mix precommit.

Dependencies

Depends on the exact-receipt timeline work and #33.