Markdown Preview Copy/Paste Does Not Preserve Formatting in GitHub Copilot Desktop

### Feature summary

Markdown Preview Copy/Paste Does Not Preserve Formatting in GitHub Copilot Desktop

### What problem are you trying to solve?

# Markdown Preview Copy/Paste Does Not Preserve Formatting in GitHub Copilot Desktop

## Summary

When viewing generated Markdown content in the GitHub Copilot Desktop app, I can switch from the raw Markdown view to the rendered **Markdown Preview** view. However, when I copy content from the Preview view and paste it into a word processor (for example, Microsoft Word), the formatting is not preserved.

In Visual Studio Code, copying from the Markdown Preview retains rich text formatting such as headings, lists, tables, bold/italic text, and links when pasted into a compatible word processor. I would like the GitHub Copilot Desktop app to provide the same experience.

## Steps to Reproduce

1. Generate or open Markdown content in GitHub Copilot Desktop.
2. Switch from the Markdown source view to the rendered Markdown Preview.
3. Select content in the Preview pane.
4. Copy the content.
5. Paste into a word processor such as Microsoft Word.

## Actual Behavior

- Content is pasted as plain text or with limited formatting.
- Markdown structure and rich formatting are not fully preserved.

## Expected Behavior

Copying content from the Markdown Preview should place rich text (HTML/RTF) on the clipboard, similar to VS Code.

Formatting should be preserved when pasted into common word processors, including:

- Headings
- Bulleted and numbered lists
- Tables
- Bold and italic text
- Hyperlinks
- Code blocks (where applicable)

## Business Impact

Many users generate documents, proposals, reports, meeting notes, and presentations in Copilot and then transfer that content into their preferred word-processing application. Preserving formatting would improve productivity, reduce manual rework, and provide consistency with the experience available in Visual Studio Code.

## Suggested Enhancement

Implement clipboard support for rich-text formats (HTML/RTF) when copying content from the Markdown Preview pane, matching the behaviour of VS Code's Markdown Preview experience.

## Additional Context

As a user, I frequently generate content in Copilot and then paste it into Microsoft Word for further editing and distribution. Having formatting preserved directly from the Preview experience would significantly improve the authoring workflow and eliminate the need for manual reformatting.

### Proposed solution

_No response_

### Workflow impact

_No response_

### Installation context

_No response_

### Additional context

_No response_

Start at the rendered Markdown Preview pane and inspect how its selected content is copied; compare the behavior described for VS Code. Done means copying places rich HTML/RTF content on the clipboard so headings, lists, tables, emphasis, links, and applicable code blocks retain formatting when pasted into compatible word processors.

Written by the indexing model from the issue text.