Enhance Customer model to include role attribute and update related components

- Added a new `role` attribute to the `Customer` model in `customer.dart` and updated the corresponding generated files.
- Modified the `AuthViewModel` to set the user role based on the logged-in user's role.
- Updated UI components in `TenderDetailActions` and `DesktopTendersPage` to conditionally render elements based on the user's role.
- Refactored tests to validate the new role attribute in the `Customer` model.

test/model/customer_test.dart

@@ -23,6 +23,7 @@ void main() {
         'employee_count': 50,
         'annual_revenue': 1000000,
         'founded_year': 2015,
+        'role': 'admin',
         'is_verified': true,
         'is_compliant': false,
         'compliance_notes': 'Pending documents',
@@ -60,6 +61,7 @@ void main() {
       expect(customer.id, '123');
       expect(customer.firstName, 'John');
       expect(customer.lastName, 'Doe');
+      expect(customer.role, 'admin');
       expect(customer.isVerified, true);
       expect(customer.isCompliant, false);
       expect(customer.address?.city, 'Tehran');
@@ -106,6 +108,7 @@ void main() {
         employeeCount: 200,
         annualRevenue: 5000000,
         foundedYear: 2010,
+        role: 'admin',
         isVerified: false,
         isCompliant: true,
         complianceNotes: 'Verified',
@@ -150,6 +153,7 @@ void main() {
         employeeCount: 50,
         annualRevenue: 1000000,
         foundedYear: 2015,
+        role: 'admin',
         isVerified: true,
         isCompliant: true,
         complianceNotes: 'OK',
@@ -184,10 +188,12 @@ void main() {
 
       final updated = customer.copyWith(
         firstName: 'NewName',
+        role: 'analyst',
         isVerified: false,
       );
 
       expect(updated.firstName, 'NewName');
+      expect(updated.role, 'analyst');
       expect(updated.isVerified, false);
       expect(updated.id, '123');
     });
@@ -199,6 +205,7 @@ void main() {
 
       expect(customer.id, isNull);
       expect(customer.firstName, isNull);
+      expect(customer.role, isNull);
       expect(customer.isVerified, isNull);
     });
 
@@ -207,6 +214,7 @@ void main() {
         'id': 'A1',
         'first_name': 'Ali',
         'last_name': 'Rezaei',
+        'role': 'admin',
         'is_verified': true,
         'address': {'city': 'Tehran'},
         'contactPersons': {'first_name': 'Sara', 'is_primary': true},
@@ -217,6 +225,7 @@ void main() {
 
       expect(output['id'], 'A1');
       expect(output['first_name'], 'Ali');
+      expect(output['role'], 'admin');
       expect(output['is_verified'], true);
       final addressJson = (output['address'] as Address).toJson();
       final contactJson = (output['contactPersons'] as ContactPerson).toJson();