Copilot seat REST API: read subscription vs grant seats vs check one user

This sheet compares GET org copilot billing, POST billing selected_users, GET member's copilot seat.

CriterionGET org copilot billingPOST billing selected_usersGET member's copilot seat
UseRead org subscription: seat breakdown and feature policiesGrant seats to named individuals outside a teamCheck one user's seat and activity

The verdict, the full comparison, 3 rules and 3 traps are part of GH-300 access. Unlock GH-300.