Stage 20 — Classwork API
GET /api/v1/classwork/
Protected by Stage 10 bearer authentication. Read-only. Pupil/student access is limited to their class; parent access is limited to classes containing their children; approved staff/admin roles may query classwork.
Filters: class_id, subject, session, term, date, limit, offset.
Binary contents are intentionally not returned; has_content indicates whether content exists.
