Show provisioning requesters and reserve Maxis for system actions

src/lib/auth.ts

@@ -1,5 +1,8 @@
 export type UserRole = 'admin' | 'operator' | 'viewer';
 
+/** Reserved identity for work requested by the controller. */
+export const systemUsername = 'Maxis';
+
 export interface AuthUser {
     id: string;
     username: string;