feat: update DocumentsRepositoryImpl to include mock staff documents with detailed attributes

apps/mobile/packages/features/staff/profile_sections/compliance/documents/lib/src/data/repositories_impl/documents_repository_impl.dart

@@ -23,6 +23,31 @@ class DocumentsRepositoryImpl implements DocumentsRepository {
       throw Exception('User not authenticated');
     }
 
+    /// MOCK IMPLEMENTATION
+    /// To be replaced with real data connect query when available
+    return [
+      domain.StaffDocument(
+        id: 'doc1',
+        staffId: currentUser.uid,
+        documentId: 'd1',
+        name: 'Work Permit',
+        description: 'Valid work permit document',
+        status: domain.DocumentStatus.verified,
+        documentUrl: 'https://example.com/documents/work_permit.pdf',
+        expiryDate: DateTime.now().add(const Duration(days: 365)),
+      ),
+      domain.StaffDocument(
+        id: 'doc2',
+        staffId: currentUser.uid,
+        documentId: 'd2',
+        name: 'Health and Safety Training',
+        description: 'Certificate of completion for health and safety training',
+        status: domain.DocumentStatus.pending,
+        documentUrl: 'https://example.com/documents/health_safety.pdf',
+        expiryDate: DateTime.now().add(const Duration(days: 180)),
+      ),
+    ];
+
     try {
       final QueryResult<ListStaffDocumentsByStaffIdData,
               ListStaffDocumentsByStaffIdVariables> result =