[BUG] Windows absolute paths in markdown links: false affordance (renders clickable, click does nothing)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Continuing from Issue 10846

Regression report — Windows absolute paths in markdown links: false affordance (renders clickable, click does nothing)

Reproducing on the current Claude Code VSCode extension on Windows 11.

Two distinct failure modes observed:

1. [file.cs](relative/workspace/path.cs)

→ Clickable, opens file correctly ✅

1. c:\absolute\windows\path.md (code span)

→ Not rendered as a link — acceptable

1. [text](c:\absolute\windows\path.md) (markdown link syntax)

→ Renders blue with hover cursor change, but click performs NO ACTION

The third case is the problem — the link has the full visual affordance of an
interactive element but silently does nothing on click. No error, no file picker,
no navigation. Observed on links generated by Claude pointing to files outside
the workspace root (e.g. c:\Code\.agent\output\).

Relative workspace-root paths work correctly, so the issue is specific to
absolute Windows paths in markdown link syntax.

Environment:

• OS: Windows 11 Pro
• Shell: bash (Git Bash)
• Extension: Claude Code VSCode extension (current version)

Previously tracked as a duplicate in #27672. Noting here as the root issue since
the false-affordance case (looks interactive, does nothing) is the most
user-confusing variant — worse UX than simply not rendering a link at all.

What Should Happen?

Links produced in the output should function if presented as functional.

Error Messages/Logs

Steps to Reproduce

1. Create an output to the VS Code Claude extension with three links:
2. [file.cs](relative/workspace/path.cs)

→ Clickable, opens file correctly ✅

1. c:\absolute\windows\path.md (code span)

→ Not rendered as a link — acceptable

1. [text](c:\absolute\windows\path.md) (markdown link syntax)

→ Renders blue with hover cursor change, but click performs NO ACTION

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.81 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_