add brain

.brain/.agent/skills/engineering-advanced-skills/changelog-generator/references/changelog-formatting-guide.md

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+# Changelog Formatting Guide
+
+Use Keep a Changelog section ordering:
+
+1. Security
+2. Added
+3. Changed
+4. Deprecated
+5. Removed
+6. Fixed
+
+Rules:
+
+- One bullet = one user-visible change.
+- Lead with impact, not implementation detail.
+- Keep bullets short and actionable.
+- Include migration note for breaking changes.

.brain/.agent/skills/engineering-advanced-skills/changelog-generator/references/ci-integration.md

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+# CI Integration Examples
+
+## GitHub Actions
+
+```yaml
+name: Changelog Check
+on: [pull_request]
+
+jobs:
+  changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: python3 engineering/changelog-generator/scripts/commit_linter.py \
+          --from-ref origin/main --to-ref HEAD --strict
+```
+
+## GitLab CI
+
+```yaml
+changelog_lint:
+  image: python:3.12
+  stage: test
+  script:
+    - python3 engineering/changelog-generator/scripts/commit_linter.py --to-ref HEAD --strict
+```

.brain/.agent/skills/engineering-advanced-skills/changelog-generator/references/monorepo-strategy.md

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+# Monorepo Changelog Strategy
+
+## Approaches
+
+| Strategy | When to use | Tradeoff |
+|----------|-------------|----------|
+| Single root changelog | Product-wide releases, small teams | Simple but loses package-level detail |
+| Per-package changelogs | Independent versioning, large teams | Clear ownership but harder to see full picture |
+| Hybrid model | Root summary + package-specific details | Best of both, more maintenance |
+
+## Commit Scoping Pattern
+
+Enforce scoped conventional commits to enable per-package filtering:
+
+```
+feat(payments): add Stripe webhook handler
+fix(auth): handle expired refresh tokens
+chore(infra): bump base Docker image
+```
+
+**Rules:**
+- Scope must match a package/directory name exactly
+- Unscoped commits go to root changelog only
+- Multi-package changes get separate scoped commits (not one mega-commit)
+
+## Filtering for Package Releases
+
+```bash
+# Generate changelog for 'payments' package only
+git log v1.3.0..HEAD --pretty=format:'%s' | grep '^[a-z]*\(payments\)' | \
+  python3 scripts/generate_changelog.py --next-version v1.4.0 --format markdown
+```
+
+## Ownership Model
+
+- Package maintainers own their scoped changelog
+- Platform/infra team owns root changelog
+- CI enforces scope presence on all commits touching package directories
+- Root changelog aggregates breaking changes from all packages for visibility