improvement: DRY GetActiveNotebooks tool and ActiveNotebooks prompt and improve outputs

[bjoaquinc]

📝 Summary

This moves getting all active notebooks to ToolContext so it can be accessed by both GetActiveNotebooks tool and ActiveNotebooks prompt.

🔍 Description of Changes

It also does the following:

• Add better handling of no filepath (for new notebook that hasn't been saved yet)
• Remove unused or redundant notebook info for both tool and prompt
• Create a base MarimoNotebookInfo dataclass where sessionId is not Optional
• Change next-steps in GetActiveNotebooks from GetCellRuntimeData to GetNotebookErrors since it makes more sense
• Change from using filename (or relative filepath) to always using absolute filepath for agent edit notebook tools
• Improve GetActiveNotebooks tests

📋 Checklist

• I have read the contributor guidelines.
• For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on Discord, or the community discussions (Please provide a link if applicable).
• I have added tests for the changes made.
• I have run the code and verified that it works as expected.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
marimo-docs	Ready	Preview	Comment	Oct 29, 2025 1:55am

[mscolnick]

nice cleanup