fix: remove SVG <title> tooltip from marimo icons

[daizutabi]

📝 Summary

This is a follow-up to PR #8471.

PR #8471 added an inline <title> to MarimoIcon to satisfy an a11y lint rule. However, browsers render SVG <title> as a native hover tooltip, which shows up in the UI (e.g., in the file tree) and breaks the app's look and feel.

🔍 Description of Changes

• Remove the inline <title> from MarimoIcon (prevents the native hover tooltip)
• Add aria-hidden={true} to the <svg>

📋 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).
• Tests have been added for the changes made.
• Documentation has been updated where applicable, including docstrings for API changes.
• Pull request title is a good summary of the changes - it will be used in the release notes.

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Mar 6, 2026 10:17am

[github-actions]

🚀 Development release published. You may be able to view the changes at https://marimo.app?v=0.20.5-dev19