Enhance employee and user management with linked user functionality

- Introduced `EmployeeUserWrite` type to manage user details associated with employees.
- Updated `EmployeesService` and `EmployeesRepository` to support user assignment and retrieval by user ID.
- Enhanced DTOs to include user information for employee creation and updates.
- Implemented validation to ensure proper handling of user data during employee operations.
- Added unit and e2e tests to validate the new functionality and ensure data integrity in user-employee relationships.
- Modified existing controllers to accommodate the new user linkage features in employee management.

src/modules/configuration/employees/employees.repository.spec.ts

@@ -107,6 +107,12 @@ describe('EmployeesRepository', () => {
     expect(employee?.code).toBe('EMP_01');
   });
 
+  it('findByUserId maps a row', async () => {
+    limit.mockResolvedValueOnce([row]);
+    const employee = await repository.findByUserId('user-1');
+    expect(employee?.id).toBe('emp-1');
+  });
+
   it('list returns mapped rows and total', async () => {
     select
       .mockImplementationOnce(() => ({