- Auto-enrollment on startup when certs are missing/invalid and enrollment.manager_url configured
- Certificate validation (existence, parse, expiry, key match, CA trust)
- --enroll exits after completion (no port conflict with systemd service)
- --renew-certs flag for manual cert renewal
- SO_REUSEADDR on TcpListener::bind (prevents Address already in use)
- Polling token persistence for enrollment resume after restart
- Exit code strategy (0=clean, 1=error, 2=enrollment in progress)
- HTTP 409 (host already exists) handling during enrollment
- Move 'Listening on' log after actual bind
- Increase RestartSec to 10s and add StartLimitBurst=5
- Postinst checks for certs and enrollment URL, prints guidance
- EnrollmentConfig.manager_url changed to Option<String>
- cert_renewal_threshold_days and polling_token config fields
- Updated SPEC.md and DEPLOYMENT_GUIDE.md with new workflow
- RCA document for crash loop root cause analysis
- Version bumped to 1.2.0
- New src/packages/cache.rs module with PackageCacheState, stale detection,
state persistence, 404 retry logic
- Add refresh_package_cache() and last_cache_update() to PackageManagerBackend
trait, implemented on all 5 backends (APT, DNF, YUM, APK, Pacman)
- Health check now reports last_cache_update and cache_status fields,
triggers cache refresh if stale (>4h), returns degraded on failure
- Patch apply jobs now force cache refresh before applying patches,
with 404/fetch error retry (1 retry after cache refresh)
- Cache state persists to /var/lib/linux_patch_api/state/cache.json
- Version bump to 1.1.17
- Update ARCHITECTURE.md and REQUIREMENTS.md (FR-007)
Closes: #2