Staff Registration/Profile Layout Split

Updated pages:
/admin/hrms/staff_form.php              => Employee Registration Form layout when no id is supplied
/hrms/staff_register.php                => Employee Registration Form layout
/admin/hrms/staff_form.php?id=1          => Employee Profile_files layout for edit/profile mode
/hrms/staff_profile_update.php           => Employee Profile_files layout after Punch ID + DOB verification

Registration design source reference:
https://college.mdsoftware.org.in/employee/emp_registration.php

Profile/update design source:
Uploaded Employee Profile_files.zip assets copied under /assets/employee_profile_files/

Important fixes:
- department_id and designation_id now allowed for public registration request data.
- DD-MM-YYYY and DD/MM/YYYY date input is normalized to YYYY-MM-DD before saving.
- Icons continue to show using local fallback when webfonts are not present in Employee Profile_files.zip.