feat: Update API endpoint usage in repositories to remove redundant path property

- Refactored multiple repository implementations across client and staff features to directly use endpoint objects without accessing the `path` property.
- Introduced a new `FeatureGate` class for client-side feature gating based on user scopes, allowing for better access control to API endpoints.
- Added `ApiEndpoint` class to represent API endpoints with their paths and required scopes for future feature gating.

apps/mobile/packages/features/staff/home/lib/src/data/repositories/home_repository_impl.dart

@@ -17,7 +17,7 @@ class HomeRepositoryImpl implements HomeRepository {
   @override
   Future<StaffDashboard> getDashboard() async {
     final ApiResponse response =
-        await _apiService.get(StaffEndpoints.dashboard.path);
+        await _apiService.get(StaffEndpoints.dashboard);
     final Map<String, dynamic> data = response.data as Map<String, dynamic>;
     return StaffDashboard.fromJson(data);
   }
@@ -25,7 +25,7 @@ class HomeRepositoryImpl implements HomeRepository {
   @override
   Future<bool> getProfileCompletion() async {
     final ApiResponse response =
-        await _apiService.get(StaffEndpoints.profileCompletion.path);
+        await _apiService.get(StaffEndpoints.profileCompletion);
     final Map<String, dynamic> data = response.data as Map<String, dynamic>;
     final ProfileCompletion completion = ProfileCompletion.fromJson(data);
     return completion.completed;