Write widget tests for WrappedAnimationController

WrappedAnimationController likely implements State with TickerProviderStateMixin or is a standalone class accepting a TickerProvider. In tests, use `tester.pumpWidget(MaterialApp(home: TestHarness()))` where TestHarness creates the controller. To test initialisation before first frame, use `tester.pump(Duration.zero)` and inspect controller state immediately after pumpWidget. For dispose testing, grab a reference to the controller, call `tester.pumpWidget(Container())` to remove the widget from tree (triggering dispose), then assert `controller.isDisposed`.

For Rive mocking, create a `MockStateMachineController` that implements the minimum interface needed; inject it via a setter or factory parameter. If WrappedAnimationController does not currently accept a TickerProvider via injection, refactor to add a `@visibleForTesting` constructor parameter before writing tests. Avoid using `await tester.pumpAndSettle()` for animation tests — use explicit `pump(duration)` calls to control time precisely.

Widget tests using flutter_test's WidgetTester. Create a minimal test harness widget that instantiates WrappedAnimationController with a TestVSync (or by mounting it inside a StatefulWidget with SingleTickerProviderStateMixin). Test groups: 'initialisation before first frame', 'dispose lifecycle', 'play and pause state transitions', 'triggerRiveInput graceful fallback', 'triggerRiveInput with mock Rive'. Use `addTearDown(controller.dispose)` in each test to prevent leaked tickers.

Use `expect(tester.takeException(), isNull)` after triggerRiveInput with null Rive to verify no exception propagates. Mock RiveFile loading using a stub that returns an empty RiveFile or null.