Backend: Examiner Notes API & database (strr-api)

[jimmypalelil]

🔗 Design (HLD): link

Summary

Implement Data Model & API for Examiner Notes feature as per the HLD linked above

Database

Alembic revision: examiner_notes table (DDL in HLD)

API

Check HLD for the request & response schemas

Method	Path
GET/POST	/api/v1/applications/{application_number}/notes
GET/POST	/api/v1/registrations/{registration_id}/notes

Acceptance criteria

• Migration up/down; XOR constraint enforced
• Four endpoints match HLD request/response and status codes
• Application POST blocked when registered or disallowed status
• GET returns newest ≤500 with truncated when more exist
• Swagger updated
• Unit & Integration tests added