add molab share action

[Light2Dark]

📝 Summary

Adds molab share action which opens up molab.marimo.io/new#code/... in a new tab. This is shown if either sharing option is enabled, but not shown if both are disabled.

Screen.Recording.2026-04-16.at.12.03.07.AM.mov

📋 Pre-Review Checklist

• 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).
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✅ Merge Checklist

• I have read the contributor guidelines.
• Documentation has been updated where applicable, including docstrings for API changes.
• Tests have been added for the changes made.

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Apr 15, 2026 4:11pm

[Copilot]

Pull request overview

Adds a new “Create molab notebook” share action in the editor, generating a compressed #code/... URL and opening it in a new tab targeting molab.

Changes:

• Add a Constants.molab base URL.
• Add a Share dropdown action that reads notebook code, builds a shareable link with a molab /new base, and opens it in a new tab.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
frontend/src/core/constants.ts	Adds a new molab base URL constant used for sharing.
frontend/src/components/editor/actions/useNotebookActions.tsx	Adds a Share menu item to create/open a molab notebook from current code.

[akshayka]

Looks great!