[BUG] Cowork Windows: cowork-vm-nat HNS network never created, bridge sockets fail on every session

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 fails on every session with "Failed to create bridge sockets after 5 attempts".

Root cause identified through log analysis: cowork-vm-nat HNS network is never created.
Get-HnsNetwork only shows Default Switch. The VM boots successfully (confirmed via hcsdiag list)
but the bridge socket layer fails because the NAT network doesn't exist.

Suspicious log line: [VM:steps] create_network completed (0ms) — network creation completes
instantly, suggesting it is silently no-oping rather than actually creating the HNS network.

CoworkVMService is running. VM boots and SDK installs successfully. API is reachable.
Only the bridge socket step fails.

What Should Happen?

Cowork session should start successfully and execute tasks

Error Messages/Logs

[warn] [vm-stderr] Error: Failed to create bridge sockets after 5 attempts
[info] [VM:steps] create_network completed (0ms)
[info] [Process] Exited, code=1, signal=null, duration=1023ms, oom=false

Steps to Reproduce

1. Open Claude Desktop
2. Switch to Cowork tab
3. Start any new session
4. Session immediately fails with "Claude Code process exited with code 1"

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

unknown

Claude Code Version

1.3036

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Get-HnsNetwork shows only "Default Switch" — cowork-vm-nat is never created.
VM boots successfully (hcsdiag list confirms running VM).
CoworkVMService is running. HypervisorPlatform and VirtualMachinePlatform both enabled.
ESET Smart Security installed. Windows 11 Pro. Claude Desktop version 1.3036.