GET/v1/lessons/:id
Auth: tenant — Status: stable
Fetch one lesson by id. Tenant-scoped: a leaked id never surfaces another tenant's row.
curl -H "Authorization: Bearer atr_…" \
http://arbiter.example.com/v1/lessons/14
Response
200 OK
Same lesson shape as POST/v1/lessons.
Failure modes
| Status | When |
|---|---|
| 401 | Missing / invalid bearer. |
| 404 | Lesson not found for this tenant. |