feat(receipt-import): add refresh categories endpoint and UI integration

Co-authored-by: Copilot <copilot@github.com>

flutter/lib/features/profile/data/profile_repository.dart

@@ -41,4 +41,12 @@ class ProfileRepository {
     );
     return UserProfile.fromJson(data);
   }
+
+  Future<void> refreshCategories() async {
+    final token = await _ref.read(authStateProvider.future);
+    await guardedApiCall(
+      _ref,
+      () => _apiClient.postJson(ReceiptImportApiPaths.refreshCategories, body: {}, token: token),
+    );
+  }
 }