- Added a new helper function `CaptureHarnessScreenshot` to encapsulate SDL screenshot logic.
- Updated `ImGuiTestHarnessServiceImpl::Screenshot` to utilize the new screenshot helper.
- Enhanced `TestManager::CaptureFailureContext` to automatically capture screenshots and widget state on test failures.
- Introduced new fields in the `GetTestResultsResponse` proto for screenshot path, size, failure context, and widget state.
- Updated CLI and gRPC client to expose new diagnostic fields in test results.
- Ensured that screenshots are saved in a structured directory under the system's temp directory.
- Improved logging for auto-capture events, including success and failure messages.
