Get a school-platform admin user by its ID. PERMISSIONS describes the user's permission level, not the API key's access rights: 0 = Analyst, 1 = User, 4 = Admin, 5 = Owner. Values 2 and 3 are reserved; user creation and permission updates map them to 1. API keys cannot create or assign the Owner role. LAST_LOGIN is the latest recorded login within the 12-month login-log retention window; null means no login was recorded in that window and does not necessarily mean the user has never connected.