Enhance staff application flow with email verification checks, refined error handling, and improved user feedback in frontend and backend.

open_api/src/main/resources/schemas/forms/staff_apply/staff_apply.yml

@@ -66,7 +66,6 @@ components:
           description: Preferred pronouns of the applicant
         joinDate:
           type: string
-          maxLength: 256
           format: date
           description: Date when the applicant joined the service
         weeklyPlaytime: