Cowork tab not shown on Snapdragon X (ARM64) — yukonSilver unsupported loop

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?

Cowork tab does not appear in the main Claude Desktop window (only Chat and Code tabs visible), despite CoworkVMService running and the ARM64-specific installer being used.

Every startup, cowork_vm_node.log shows this loop:
[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
[VM] Loading vmClient (TypeScript) module...
[VM] Module loaded successfully

The VM bundle is deleted on every launch and never persists. No vm_bundle files are found on disk. The Cowork section exists in Settings but the tab never appears.

What Should Happen?

Cowork tab should appear in the main window alongside Chat and Code, and the VM bundle should initialize successfully on Snapdragon X ARM64.

Error Messages/Logs

From cowork_vm_node.log (repeats on every launch):
2026-04-19 11:42:51 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-19 11:42:52 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-19 11:42:52 [info] [VM] Module loaded successfully

From main.log:
Update URL: https://api.anthropic.com/api/desktop/win32/arm64/msix/update
LocalAgentModeSessions.getSupportedCommands: sessionId=undefined, cwd=undefined

Steps to Reproduce

1. Download ARM64-specific Claude Desktop installer (dedicated Snapdragon link from r/snapdragon post)
2. Install on Microsoft Surface Pro 11 (Snapdragon X, X1P64100)
3. Launch Claude Desktop
4. Observe: only Chat and Code tabs appear, no Cowork tab
5. Check cowork_vm_node.log — yukonSilver unsupported loop repeats on every launch

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Latest ARM64 MSIX (confirmed via Help → Check for Updates: "You are running the latest version")

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Device: Microsoft Surface Pro 11 (SKU: Surface_Pro_11th_Edition_2076)
CPU: Snapdragon X, 10-core X1P64100 @ 3.40GHz, 16GB RAM
CoworkVMService: confirmed running (sc query returns "An instance of the service is already running")
No vm_bundle files found anywhere on disk.

Related issues: #40198, #30566