Embed visualizations inline in Claude Desktop via (CSP bypass)

[SuMayaBee]

Description

Claude Desktop blocks localhost iframes via CSP, so visualizations never loaded there.

This PR fixes that by rendering each snippet as a self-contained HTML page and injecting it directly via iframe.srcdoc instead of loading it by URL. The HTML is compressed before delivery to stay within context limits. If the code uses Python callbacks that won't work without a live server, a placeholder is shown instead of a broken widget.

Other clients (Cursor, VS Code) are unaffected.

Screen Recording

Claude Desktop

1. generate 2 random cols and plot a scatter plot (will show inline)
2. plot a sine wave (will show inline)
3. create a click me button and it will show how many times I clicked (Need server, showed a button to open in browser)

Claude.Desktop.mp4

Cursor/VScode (Not affected)

(Ask anything, it won't changed and always shows inline with iframe)

1. generate 2 random cols and plot a scatter plot.
2. plot a sine wave.
3. create a click me button and it will show how many times I clicked.

Cursor.mp4

AI Disclosure

• Tool & Model: Claude Code + Sonnet 4.6
• I have tested all AI-generated content in my PR.
• I take responsibility for all AI-generated content in my PR.

Checklist

• Tests added and are passing
• Added documentation

[ahuang11]

Looks great! Can you run https://holoviz-dev.github.io/holoviz-skills/contributing-to-holoviz/cleanup/ before I review in depth?

[ahuang11]

I couldn't get it working :(

https://panel-extensions.github.io/panel-live-server/tutorials/mcp-server/#step-2-verify-the-connection