[BUG] Session history empty in VSCode extension when working directory is on a mapped Windows drive

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?

Description

The Session history panel in the VSCode Claude Code extension shows only the current (empty) chat and no previous sessions.

Environment

• OS: Windows 10 Pro 10.0.19045
• Claude Code VSCode extension
• Working directory on a mapped network drive: U:\WWW\welift.it\wwwphp8\tema

Steps to reproduce

1. Open VSCode with a working directory on a mapped Windows drive (e.g. U:\)
2. Start and complete one or more Claude Code sessions
3. Click "Session history" in the Claude Code panel

Expected behavior

Previous sessions should be listed in the history panel.

Actual behavior

Only the current (empty) session is shown. No previous sessions appear.

Additional context

Session .jsonl files exist on disk at the correct path:
C:\Users\<user>\.claude\projects\u--WWW-welift-it-wwwphp8-tema\

The files are present and contain data (multiple sessions from today and previous days), so the issue appears to be in how the extension resolves or looks up the project path when the working directory uses a non-standard mapped drive letter (U:).

The sessions/ file for the active session correctly records entrypoint: "claude-vscode" and the correct cwd, so the session is being tracked — it just doesn't appear in the history UI.

Workaround: none found within the VSCode extension UI.

What Should Happen?

The Session history panel should list all previous sessions for the current project,
grouped by date (Today, Yesterday, Last 7 days, etc.), with a title or preview of
each conversation. Clicking a session should resume it with full context directly
in the VSCode panel.

The session .jsonl files already exist on disk, so the fix should ensure the
extension correctly resolves mapped Windows drive letters (e.g. U:\) when looking
up the project directory under ~/.claude/projects/.

Error Messages/Logs

Steps to Reproduce

1. Open VSCode with a working directory on a mapped Windows drive (e.g. U:\)
2. Start and complete one or more Claude Code sessions
3. Click "Session history" in the Claude Code panel

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.138

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_