Five admin endpoints under existing RequireAdmin middleware:
- GET /api/admin/invites — list active + recently-redeemed
- POST /api/admin/invites — generate 24h invite, returns
{token, expires_at, ...}. Audits ActionInviteCreate.
- DELETE /api/admin/invites/{token} — revoke unredeemed invite.
Audits ActionInviteRevoke.
- GET /api/admin/users — list all users (id, username,
display_name, is_admin, created_at).
- PUT /api/admin/users/{id}/admin — toggle is_admin with
last-admin guard. Audits ActionPromoteAdmin / ActionDemoteAdmin.
Last-admin guard counts admins, refuses demotion of the sole
admin with 409 'last_admin'. Race window between count and update
is acceptable for v1 — worst case is 'no admins left,' which the
env-driven bootstrap or CLI reset can recover from. Common path
('admin demotes themselves') is now blocked.
Adds ListUsers, CountAdmins, UpdateUserAdmin sqlc queries to
users.sql.
Tests cover: invite create/list/delete round-trip, non-admin gets
403, user list, promote happy path, last-admin demotion refused,
two-admins demotion allowed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
