[WSL2][Install] bootstrap-windows.ps1 throws unhandled exception when winget is not installed #3972

Description

On Windows machines where winget.exe is not installed (e.g. Windows Server or machines without App Installer), the NemoClaw bootstrap script bootstrap-windows.ps1 (PR #3744) completes the WSL2 setup steps successfully but then throws an unhandled PowerShell exception when attempting to install Docker Desktop, with no user-friendly guidance. The script does not offer an alternative install path (e.g. direct installer download) or a graceful skip option.

Environment

Device:        Windows PC (x86_64)
OS:            Windows (PowerShell 5.1), WSL2 Ubuntu 24.04.4 LTS
Architecture:  x86_64
NemoClaw:      v0.0.47 (installed in WSL; bootstrap did not complete)
Node.js / npm / Docker / OpenShell / OpenClaw: N/A (install not reached)

Steps to Reproduce

1. On a Windows machine without winget installed (verify: winget returns CommandNotFoundException).
2. Download the bootstrap script from PR feat: add minimal Windows bootstrap installer #3744:

   Invoke-WebRequest -Uri 'https://raw.githubusercontent.com/NVIDIA/NemoClaw/refs/pull/3744/head/scripts/bootstrap-windows.ps1' -OutFile 'bootstrap-windows.ps1'

3. Run:

   Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass -Force
   .\bootstrap-windows.ps1

4. Observe error after WSL2 setup completes.

Expected Result

Script detects missing winget and either:

• (a) provides a direct Docker Desktop installer download fallback, or
• (b) prints a clear user-friendly message with instructions to install App Installer from the Microsoft Store, then exits cleanly with a non-zero code.

Actual Result

Enabling WSL 2 Windows features...
Feature already enabled: VirtualMachinePlatform
Feature already enabled: Microsoft-Windows-Subsystem-Linux
WSL distro already registered: Ubuntu
Ubuntu is already WSL 2.
Ubuntu is ready.
winget.exe not found. Install App Installer from the Microsoft Store and re-run.
At C:\Users\local-mercl\bootstrap-windows.ps1:362 char:9
+         throw 'winget.exe not found. Install App Installer from the M ...
    + CategoryInfo          : OperationStopped: (winget.exe not ...ore and re-run.:String) [], RuntimeException
    + FullyQualifiedErrorId : winget.exe not found. Install App Installer from the Microsoft Store and re-run.

Logs

Not captured beyond terminal output above.

NVB#6198708