Require 100% (@author) attribution in CHANGELOG via release lint

[houko]

Background

About 50% of entries in the current CHANGELOG.md carry (@author), leading to incomplete contributor attribution and weak community recognition.

openclaw approach (reference)

• All 1358 entries carry Thanks @author
• AGENTS.md states explicitly: every

[houko]

This appears to be resolved on main. The full enforcement chain is in place:

1. Validator script — scripts/check-changelog-attribution.py (introduced via CHANGELOG attribution uses (@user) syntax — issue #3307 should validate that pattern, not @author: #3400) checks every newly-added [Unreleased] bullet for a trailing (@github-login) and prints offending bullets with file:line.
2. Pre-commit hook — scripts/hooks/pre-commit (Step 2b) runs --staged on every commit; reject if missing.
3. CI gate — .github/workflows/ci.yml job changelog-attribution (lines 266-281) runs on every pull_request and fails if a newly-added [Unreleased] bullet lacks (@user). Diff-scoped via BASE_SHA/HEAD_SHA.

The deliberate design choice (documented in the CI job comment at ci.yml:261-265) is to enforce on new additions only — historical pre-#3400 entries (1,800+ bullets) are intentionally exempt to avoid retroactive churn on a community-authored history. That matches the openclaw reference's forward-looking policy without the diff-noise of a one-shot backfill.

The remaining "50% un-attributed" gap mentioned in the issue body is a one-time backfill of historical entries, which the maintainers can either:

• (a) accept the existing forward-only policy and close, or
• (b) open a separate issue tracking a one-shot CHANGELOG history backfill (no new tooling needed; same script with --all-unreleased already audits any window).

Recommend closing as infrastructure complete; if a backfill is desired, that's a different request.