## Summary

<!-- Brief description of what this PR does -->

## Type of Change

- [ ] 🐛 Bug fix (non-breaking change that fixes an issue)
- [ ] ✨ New feature (non-breaking change that adds functionality)
- [ ] 💥 Breaking change (fix or feature that would break existing functionality)
- [ ] 📝 Documentation update
- [ ] 🔧 Refactor / cleanup
- [ ] 🛡️ Security fix

## Checklist

### Required
- [ ] Tests added/updated for changed behavior
- [ ] `npm run typecheck` passes (source/operator/UI plus type-level contracts; normal `.test.ts` coverage is `npm test`)
- [ ] `npm run lint` passes
- [ ] `npm test` passes
- [ ] Release claims in this PR do not treat mock or browser-mock-hub evidence as ship proof
- [ ] User-facing docs/copy stay inside current runtime evidence boundaries
- [ ] If this PR changes release-facing claims, the claim matrix / defect ledger / de-scope wording were updated to match live evidence

### If Applicable
- [ ] Migration added → migration chain is contiguous (`npm run check:migrations`)
- [ ] SSD updated → markers present (`npm run check:ssd`)
- [ ] Adversarial tests not skipped (`npm run check:adversarial`)
- [ ] API surface changed → routes documented in SSD
- [ ] Security-sensitive change → adversarial test added

### Documentation
- [ ] SSD (`docs/distributed-architecture.md`) updated if architecture changed
- [ ] README updated if user-facing behavior changed
- [ ] CHANGELOG entry added

## Related Issues

<!-- Link to related issues: Fixes #123, Closes #456 -->
