Feature Request: Extension API: Support for Docking WebView in Split Code Editor Tab

[ZgGPuo]

Feature Request: Support for Docking WebView in Split Code Editor Tab

Request
Expose API support in the VS Code Extension API to allow embedding a WebView alongside a standard text/code editor within the same tab, split vertically or horizontally.

Use Case
This would enable the creation of hybrid editors similar to Visual Studio's XAML editor where the top (or left) pane is raw code and the bottom (or right) pane is a custom-rendered visual representation (e.g., a preview, form designer, etc).
Currently, extensions can only open WebViews in full panels or in separate tab columns, but not share space within a native editor tab.

Proposal
Allow extensions to define a split layout within a single tab, where one side is a native code editor and the other is a WebView. The API could expose layout ratios and support communication between the WebView and the code side.

Impact
This would unlock powerful UI/UX workflows without requiring full custom editors or awkward multi-tab workarounds. For example, I'm currently using two tab columns to mimic this, but constantly switching and syncing between them is cumbersome.
Such an API would be particularly valuable for live preview tools, GUI designers, markdown editors, etc.

Postscript
Would love to hear your thoughts on whether this is feasible or on the roadmap!