Worked on stabilizing manifest management in the canonical/checkbox repository, focusing on improving reliability and testability. Addressed a critical issue in JavaScript and Python where ManifestBrowser would crash in interactive mode if all manifests were hidden, refactoring the manifest saving logic to correctly distinguish between interactive and non-interactive modes. Prioritized visible manifests during interactive sessions to enhance user experience and reduce the risk of user-facing crashes. Improved the structure and readability of unit tests, supporting safer deployments and enabling faster detection of future bugs. Emphasized bug fixing, refactoring, UI development, and robust unit testing throughout the development process.