[BUG] Cowork tab missing — yukonSilver marked as unsupported despite VM service running and Hyper-V enabled

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?

The Cowork tab does not appear in Claude Desktop. On every launch, cleanupVMBundleIfUnsupported marks yukonSilver as unsupported and cleans up the VM bundle before it can initialize. The VM module itself loads successfully, but is never configured.
System info:

OS: Windows 11 Home 25H2
Hyper-V: enabled
Claude Desktop: 1.3109.0.0 (MSIX, x64)
Subscription: Pro
CoworkVMService: Running

What Should Happen?

Cowork tab should appear and VM should initialize successfully. CoworkVMService is running, Hyper-V is enabled, VM module loads without errors — platform detection should not block initialization.

Error Messages/Logs

Log from cowork_vm_node.log:
[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
[VM] Loading vmClient (TypeScript) module...
[VM] Module loaded successfully
[logout] Failed to stop VM on logout: not configured: call 'configure' first

Steps to Reproduce

Install Claude Desktop (MSIX, x64) on Windows 11 Home 25H2 with Hyper-V enabled
Confirm CoworkVMService is running (Get-Service CoworkVMService)
Confirm vmms service is running (Get-Service vmms)
Launch Claude Desktop
Observe: Cowork tab does not appear
Check %LOCALAPPDATA%\Packages\Claude_pzs8sxrjxfjjc\LocalCache\Roaming\Claude\logs\cowork_vm_node.log — shows repeated yukonSilver not supported (status=unsupported) on every launch, VM never initializes

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

1.3109.0.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Same root cause as #47327, #25136, #25692. The platform detection logic incorrectly classifies this system as unsupported despite all required virtualization components being present and running