朱子纯 / test

- Backend: add GET /usr/users/{id} detail endpoint that returns the user row plus its permissionCategoryIds
- Backend: add GET /usr/permission-categories listing for the permission grid (active categories only)
- Frontend: UserDetail consumes both endpoints to populate edit form and the permission grid

Backend:
- StaffSearchVO (iIncrement / sStaffNo / sStaffName / sDepartment)
- StaffMapper.searchActive(keyword, limit) — LIKE on name + staff no
- StaffController GET /api/usr/staffs?keyword=&limit=
- UserListVO + UserMapper.xml: expose iStaffId so edit mode preserves
  the binding when user doesn't change 员工名

Frontend:
- api/staff.ts → searchStaff()
- StaffPicker.tsx: input + dropdown with debounced search, '已绑定'
  badge when an iStaffId is bound, click outside to close, search icon
- UserDetail: replace 员工名 PrimInput with StaffPicker; track iStaffId
  in form state; send to backend on save (no longer omitted)