GET /api/v1/devices/me/manifest
- Create ManifestFetcher service to fetch manifest JSON from SkillRx
- Parse and validate manifest structure
- Store manifest locally as JSON file (storage/manifest/current.json) -- we might not need it, just need to calculate checksum
- Update DeviceConfig with manifest_version, manifest_checksum, and etag
- Return parsed manifest object for sync processing
GET /api/v1/devices/me/manifest