GET /admin/users — List users for this university
POST /admin/users/invite — Create user with temp password + send email
PUT /admin/users/:id — Update role, tier, sport limitations
DELETE /admin/users/:id — Soft-deactivate user
GET /admin/periods — Reporting periods with deal counts
POST /admin/periods — Create new reporting period
GET /admin/sports — List managed sports
POST /admin/sports — Add new sport
GET /admin/peer-groups — Current peer group config
PUT /admin/peer-groups — Update peer group conferences
