Normalize math rendering in docs panel and LSP tooltips

[LiquidGunay]

📝 Summary

Fix math rendering consistency for docstrings shown in the Documentation panel and CodeMirror LSP tooltips.

🔍 Description of Changes

This PR normalizes math syntax in both rendering paths:

• Backend docs path (completion_info) in marimo/_runtime/complete.py
• Frontend LSP markdown docs path in frontend/src/core/codemirror/lsp/notebook-lsp.ts

Backend

• Added internal docstring math normalization before markdown->HTML rendering.
• Supported syntax:
  • .. math::
  • :math: inline role
  • $...$, $$...$$
  • \(...\), \[...\]
• Preserves fenced code blocks and inline code spans.
• Applied to normal docstring conversion and appended __init__ docstrings.

Frontend (LSP)

• Added frontend/src/core/codemirror/lsp/normalize-markdown-math.ts.
• Normalizes markdown math into <marimo-tex ...> while preserving fenced/inline code.
• Also normalizes LSP MarkupContent docs returned as kind: plaintext when math markers are present by converting them to markdown for rendering.
• Keeps non-math plaintext docs unchanged.
• Applied in LSP client responses for:
  • hover
  • completion docs
  • completion item resolve docs
  • signature + parameter docs

Tests

• Added backend tests in tests/_runtime/test_complete.py for math normalization and code-block safety.
• Added frontend utility tests in frontend/src/core/codemirror/lsp/__tests__/normalize-markdown-math.test.ts.
  • Includes plaintext-math vs non-math plaintext behavior.
• Extended LSP client tests in frontend/src/core/codemirror/lsp/__tests__/notebook-lsp.test.ts.
  • Added regression coverage for plaintext completion docs containing .. math::.

Validation run

• uvx hatch run +py=3.12 test:test tests/_runtime/test_complete.py
• cd frontend && pnpm test src/core/codemirror/lsp/__tests__/notebook-lsp.test.ts src/core/codemirror/lsp/__tests__/normalize-markdown-math.test.ts

Screenshot

📋 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.

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Feb 14, 2026 9:33am

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[LiquidGunay]

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