[BUG] VS Code Extension fails to activate on Windows - command 'claude-vscode.editor.openLast' not found

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?

Environment

• OS: Windows 11 x64 (10.0.26200)
• VS Code: 1.119.0
• Claude Code Extension: 2.1.136 (win32-x64)
• Claude Code CLI: 2.1.136
• Node.js: 22.22.1

Bug Description

The Claude Code VS Code extension installs successfully but never activates.
The extension does not appear in the Extension Host logs, and all commands fail with "not found".

Symptoms

• CLAUDE CODE tab shows infinite spinner
• command 'claude-vscode.editor.openLast' not found error on click
• No anthropic.claude-code folder in Extension Host logs directory
• Output: Show Output Channels does not show Claude Code channel
• CLI works fine (claude --version returns 2.1.136)
• Auth is valid (claude auth status shows logged in)

Steps to Reproduce

1. Install Claude Code extension from VS Code Marketplace on Windows
2. Restart VS Code
3. Click CLAUDE CODE tab

What I tried

• Reinstalled extension multiple times
• Reinstalled CLI via npm install -g @anthropic-ai/claude-code
• Patched hardcoded file:///home/runner/work/... paths in extension.js
• Fixed malformed settings.json
• Re-authenticated via claude auth login
• None of the above resolved the issue

What Should Happen?

Expected Behavior

Extension should activate on startup (onStartupFinished) and register commands.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Code extension (anthropic.claude-code) from VS Code Marketplace on Windows
2. Ensure Claude Code CLI is installed: npm install -g @anthropic-ai/claude-code
3. Restart VS Code completely
4. Click the CLAUDE CODE tab in the panel

Expected: Extension activates and shows session UI
Actual: Infinite spinner, clicking tab shows error "command 'claude-vscode.editor.openLast' not found"

Additional notes:

• Extension does not appear in Extension Host logs folder (no anthropic.claude-code folder)
• Claude Code channel does not appear in Output panel
• CLI works fine in terminal (claude --version = 2.1.136, claude auth status = logged in)
• Patching hardcoded file:///home/runner/work/claude-cli-internal/... path in extension.js did not resolve the issue

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.136 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_