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/domain/lib/src/exceptions/app_exception.dart

@@ -330,3 +330,22 @@ class NotAuthenticatedException extends AppException {
   @override
   String get messageKey => 'errors.auth.not_authenticated';
 }
+
+/// Thrown when the user lacks the required scopes to access an endpoint.
+class InsufficientScopeException extends AppException {
+  /// Creates an [InsufficientScopeException].
+  const InsufficientScopeException({
+    required this.requiredScopes,
+    required this.userScopes,
+    super.technicalMessage,
+  }) : super(code: 'SCOPE_001');
+
+  /// The scopes required by the endpoint.
+  final List<String> requiredScopes;
+
+  /// The scopes the user currently has.
+  final List<String> userScopes;
+
+  @override
+  String get messageKey => 'errors.generic.insufficient_scope';
+}