git diff <base>...HEAD --stat to identify changed files and scope## Summary
<!-- one-paragraph executive summary: what changed and why -->
## Changes
| Category | Files | Key change |
|----------|-------|------------|
| source | `src/auth.ts` | added OAuth2 PKCE flow |
| test | `tests/auth.test.ts` | covers token refresh edge case |
| config | `.env.example` | new `OAUTH_CLIENT_ID` var |
## Why
<!-- link to issue/ticket + one sentence on motivation -->
## Testing
- [ ] unit tests pass (`npm test`)
- [ ] manual smoke test on staging
- [ ] no coverage regression
## Risks & Rollback
- **Breaking?** yes / no
- **Rollback**: revert this commit; no migration needed
- **Risk level**: low / medium / high — because ___
Add checklist sections only when the matching file category appears in the diff:
| File category | Checklist items |
|---|---|
| source | no debug statements, functions <50 lines, descriptive names, error handling |
| test | meaningful assertions, edge cases, no flaky tests, AAA pattern |
| config | no hardcoded secrets, env vars documented, backwards compatible |
| docs | accurate, examples included, changelog updated |
security-sensitive (auth, crypto, token, password in path) |
input validation, no secrets in logs, authz correct |
When diff exceeds 20 files or 1000 lines, suggest splitting by feature area:
git checkout -b feature/part-1
git cherry-pick <commits-for-part-1>
resources/implementation-playbook.md — Python helpers for automated PR analysis, coverage reports, and risk scoring