Check decision and release-note records for changed contracts #2679

Problem

The accepted Base governance design and implementation plan identify package 11d as a required deliverable. This issue translates that package into a reviewed, bounded issue/PR train; it does not authorize implementation before the issue reaches Ready.

Expected behavior

Add deterministic evidence checks that material design decisions link to an accepted ADR/decision record and each PR has a release-note line or reasoned none. Distinguish repository-local CHANGELOG.md from externally stored release-note sources. Keep README work last and avoid treating a missing ADR as proof a decision was absent.

Scope and non-goals

Scope: Add deterministic evidence checks that material design decisions link to an accepted ADR/decision record and each PR has a release-note line or reasoned none. Distinguish repository-local CHANGELOG.md from externally stored release-note sources. Keep README work last and avoid treating a missing ADR as proof a decision was absent.

Non-goals: Do not silently expand scope, activate unreviewed policy, mirror issue fields onto PRs, grant agents merge/release authority, or make changes outside the named affected areas. Any new product decision or materially new work gets a separate issue and decision record.

Affected areas

• ADR index/schema, PR impact validator, release-note contract, CHANGELOG.md and governance CI.
• Accepted source: governance design and implementation plan, PR #2664
• Parent tracker: #2665

Impact and evidence

1. Product intent: Implements only the accepted governance design and plan; any product-requirement change must be filed separately.
2. Architecture and contracts: Destination is the package-specific section of the merged governance design/implementation plan plus the affected canonical contract named above.
3. User guidance: The issue identifies likely guidance paths; the implementation PR must name updated user/FAQ/README paths or give a change-specific reason why none is affected.
4. CLI/API and reference: The affected-area list determines whether CLI/API/reference docs change; the implementation PR must cite the exact reference path or justify no impact.
5. Operations and safety: No privileged automation or merge authority is implied; the PR must list operational/security effects and any rollback.
6. Validation and testing: The issue lists the planned tests; the PR must report executed validation and explain any unavailable test.
7. Examples and downstream use: The implementation PR must identify affected examples/consumers or give evidence that this change has no downstream surface.
8. Governance and contributor process: This package changes or preserves the contributor/governance contract as described in Scope; links must point to the canonical rules.
9. Decision records: No new decision is accepted by this issue; any durable deviation requires a proposed decision record and explicit maintainer acceptance.
10. Release notes: The PR must include a user-facing release-note line or a reasoned none; this issue does not pre-decide that disposition.

These are issue-stage dispositions to refine during Triage. Before Ready, every category must have its exact destination or evidence-based no-impact reason; the PR repeats the ten-category evidence for actual changes.

Open questions

• None known. If implementation exposes an unresolved contract, return this issue to Triage and record the decision before implementation continues.

Plan

• S1: One focused PR for this issue. Use Fixes #N only if no additional slice is needed; if the maintainer approves multiple PRs, name each S1…Sn here before the first is opened and use Part of #N.
• Dependencies: the P1 issue, the P5a issue, the P10 issue, the P11a issue
• Acceptance criteria:
• PR metadata includes a decision-impact disposition with a destination or evidence-based no-impact reason.
• Accepted ADR changes are linked and immutable except for the documented correction policy; superseding records link their predecessor.
• A missing release-note line/none is reported; none remains auditable but does not appear as user-facing content.
• The checker never invents, edits or approves decision or release wording.
• Validation:
• Fixtures cover accepted/new/superseding/rejected decision records and release-note versus none cases.
• Check changelog and external release source handling separately.
• Run warn-only and no-write tests.
• Risks and rollback: Automated detection can misclassify durable decisions; keep the human disposition as authority and roll back by disabling the warning.
• Decision impact: No decision is accepted merely by implementing the issue. Record the relevant accepted decision/ADR and file a superseding record if the maintainer approves a change.