[BUG] Extension fails to activate on Windows — hardcoded Linux path in extension.js (v2.1.136)

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 Claude Code VS Code extension v2.1.136 fails to activate on Windows due to a hardcoded Linux build path embedded
in extension.js.

Error from exthost.log:
2026-05-09 00:46:07.828 [error] Activating extension Anthropic.claude-code failed due to an error:
TypeError: The argument 'filename' must be a file URL object, file URL string,
or absolute path string. Received 'file:///home/runner/work/claude-cli-internal/
claude-cli-internal/build-agent-sdk/sdk.mjs'
at Object.<anonymous> (c:\Users\sshunko\.vscode\extensions\
anthropic.claude-code-2.1.136-win32-x64\extension.js:103:5579)

Steps to reproduce:

1. Install anthropic.claude-code v2.1.136 on Windows
2. Open VS Code
3. Click Claude icon in sidebar — panel spins indefinitely and never loads

Expected behavior: Extension activates normally.

Actual behavior: Extension fails with TypeError — the build artifact contains an absolute Linux path
(/home/runner/work/...) instead of a relative or Windows-compatible path.

Environment:

• OS: Windows 11 Pro 10.0.26200
• VS Code extension: anthropic.claude-code v2.1.136 (win32-x64)
• Claude CLI: v2.1.136

Workaround: Rolling back to v2.1.0 resolves the issue.

What Should Happen?

xtension activates successfully on Windows and the Claude panel loads without errors.

Error Messages/Logs

2026-05-09 00:46:07.828 [error] Activating extension Anthropic.claude-code failed due to an error:
  TypeError: The argument 'filename' must be a file URL object, file URL string, or absolute path string. Received
  'file:///home/runner/work/claude-cli-internal/claude-cli-internal/build-agent-sdk/sdk.mjs'
      at Object.<anonymous>
  (c:\Users\sshunko\.vscode\extensions\anthropic.claude-code-2.1.136-win32-x64\extension.js:103:5579)

Steps to Reproduce

1. Install anthropic.claude-code v2.1.136 on Windows (win32-x64)
2. Open VS Code
3. Open Claude panel via sidebar icon
4. Panel spins indefinitely and never loads

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.0

Claude Code Version

2.1.136 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

The extension.js bundle contains a hardcoded absolute Linux CI path
(/home/runner/work/claude-cli-internal/...) which is invalid on Windows.
Rolling back to v2.1.0 resolves the issue immediately.