Windows Desktop regression: local links in rendered Markdown do not open in configured VS Code target

Summary

In Codex Desktop for Windows, local file links inside the rendered preview of a local Markdown document are visibly clickable but do not open the target in the configured editor. The top-right Open in VS Code action works for the Markdown document itself, so VS Code discovery and the configured open target are working. The failure is specific to links rendered inside the Markdown document.

This worked in an earlier Codex Desktop build and is a regression.

Environment

• Codex Desktop: 26.707.3748
• OS: Windows 11 Enterprise, 10.0.26200, x64
• Configured open target: VS Code
• ~/.codex/config.toml: [desktop.open-in-target-preferences] global = "vscode"
• Subscription: not relevant to the local renderer / not disclosed

Minimal reproduction

Create two Markdown files on a normal Windows drive:

D:\temp\codex-link-repro\target.md

# Target

Synthetic local target.

D:\temp\codex-link-repro\index.md

# Local link test

[Absolute Windows path](<D:/temp/codex-link-repro/target.md>)

[Same-folder relative path](<target.md>)

Then:

1. Open index.md in Codex Desktop's rendered Markdown/artifact preview.
2. Click either link.
3. Observe that the link does not open target.md in VS Code.
4. Click the top-right Open in VS Code button for index.md.
5. Observe that index.md opens in VS Code correctly.

I also tested vscode://file/D:/temp/codex-link-repro/target.md. It does not provide a usable workaround from the rendered Markdown preview.

Actual behavior

• The local Markdown links render as blue/clickable file links.
• Clicking them does not open the target in VS Code.
• Absolute and relative local paths both fail.
• The top-right Open in VS Code action still works.

Expected behavior

Clicking a local file link in a rendered Markdown document should open the linked file using the configured open target (vscode), or at least expose an explicit Open in VS Code action for that link.

The Markdown renderer's local-link dispatch should honor the same desktop.open-in-target-preferences setting as the artifact toolbar.

Additional context

This is related to, but distinct from:

• #14883: file links in chat do nothing (this report is specifically about links inside a rendered local Markdown artifact, while the toolbar target works)
• #17649: VS Code extension chat-link regression (different surface)
• #25787: custom URI schemes such as vscode:// (supporting this could be a fallback, but normal local paths should work)
• #30722: relative Markdown links can crash/restart Codex (this report observes no navigation rather than a crash)

The current behavior makes generated Markdown indexes difficult to use: users can open the index in Codex, but every link to a referenced Markdown/PDF/source file requires an extra manual workflow despite VS Code already being the configured target.