Source Code added

mobile/lib/providers/infrastructure/cancel.provider.dart

@@ -0,0 +1,12 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+/// Provider holding a boolean function that returns true when cancellation is requested.
+/// A computation running in the isolate uses the function to implement cooperative cancellation.
+final cancellationProvider = Provider<bool Function()>(
+  // This will be overridden in the isolate's container.
+  // Throwing ensures it's not used without an override.
+  (ref) => throw UnimplementedError(
+    "cancellationProvider must be overridden in the isolate's ProviderContainer and not to be used in the root isolate",
+  ),
+  name: 'cancellationProvider',
+);