[BUG] Markdown file links in VSCode chat panel only show 'Copy link' on Windows (follow-up to #10846)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Follow-up to #10846 (auto-closed without fix).

File links in Claude Code's VSCode chat panel (e.g., [filename.ts](src/filename.ts)) do not open files on Windows. Right-clicking only shows "Copy link" — there is no "Open file" option. Left-clicking does nothing.

This significantly impacts workflow — Claude frequently references files by link, and the user must manually Ctrl+P and search for the filename every time.

What works:

• Links in Claude's "thought" actions (Read/Edit tool calls) correctly open files
• Same markdown links work when pasted into a .md file and previewed in VSCode

What doesn't work:

• Markdown file links in Claude's chat response text — right-click only shows "Copy link"

Environment

• Windows 11 Pro 10.0.26200
• VSCode (latest)
• Claude Code extension v2.1.49
• Native Windows (not WSL)

What Should Happen?

Clicking a file link in Claude's chat output should open the file in the editor, the same way links in Claude's "thought" actions work.

Steps to Reproduce

1. Open a project in VSCode on Windows
2. Open Claude Code (panel view, not terminal)
3. Ask Claude to reference a file — it responds with a markdown link like [models.py](apps/plans/models.py)
4. Right-click the link — only "Copy link" appears
5. Left-click — nothing happens