As highlighted in T412141: [MEX][Score] Introduce basic test to confirm display of musical notation statements, the current test coverage for the Score extension is limited to unit tests and end-to-end tests (Cypress). While this validates individual components in isolation, it does not fully cover real-world behaviors or ensure the extension works correctly end-to-end in typical usage scenarios.

To improve confidence in the extension’s functionality, we should introduce integration tests that verify the complete rendering workflow and validate output across supported formats, including dependencies involved in actual score generation.

Acceptance Criteria

• Add integration tests for real score rendering, covering the full rendering pipeline and requiring the LilyPond and abc2ly tools to be available in the test environment.
• Add tests for HTML output generation in ScoreFormatter, extending coverage beyond the currently tested plain/wiki formats to ensure HTML rendering behaves correctly.