Enforce staff-only assignments

backend/src/main/resources/db/migration/V16__activate_all_employees.sql

@@ -0,0 +1,5 @@
+-- Activate all employees in the users table so they appear in dropdowns
+UPDATE users u
+SET u.active = TRUE
+WHERE u.role IN ('STAFF', 'ADMIN')
+  AND EXISTS (SELECT 1 FROM employee e WHERE e.user_id = u.id);