CSS injection in tests.

[przemyslaw-zan]

🚀 Summary

ckeditor5-dev/.changelog/20260710160000_ci_4265.md

Line 9 in 552ff58

The `manualTestsPlugin()` plugin now loads the package theme entry stylesheet (`theme/index.css`) in manual tests. Package stylesheets are imported by the package entry module (`src/index.ts`), not by individual source modules, so manual tests that import source modules directly would otherwise render without the package's own styles. The import is appended to the entry script of every discovered manual page whose package has a theme entry stylesheet, preserving the cascade order of the built bundles.

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📌 Related issues

• See https://github.com/ckeditor/ckeditor5-internal/issues/4265.

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💡 Additional information

Optional: Notes on decisions, edge cases, or anything helpful for reviewers.