Update sac-enabler.ps1 to v1.3

[anmocanu]

This script enables Special Administration Console (SAC) and Serial Console boot settings on an attached OS disk's BCD store. It includes enhanced logic for Gen2 disks and improved error handling.
.VERSION
v1.3: [May 2026] - Updated the script again (current)
- Fixed breaking exception when the Hyper-V module is not installed on the host.
- Added explicit checking via Get-Module before executing nested VM discovery.
v1.2: [May 2026] - Updated the script
- Included advanced Gen2 unlettered EFI fallback and dynamic drive-letter assignment.
v0.1: Initial commit. This was the version 1.0 of the script

[EdwinBernal1]

Issues Found

🟡 Potential compatibility gap: only checks winload.exe for OS detection

The script sets $isOsPath via \windows\system32\winload.exe only. Some UEFI-oriented scenarios rely on winload.efi path detection. If winload.exe is absent or not suitable in edge images, OS detection may fail even if the disk is valid.

Recommendation: mirror the pattern used in PR #130 and check both winload.exe and winload.efi.

🟢 Minor: fallback failure path could be clearer

If no default boot entry is parsed from displayorder, the script exits with generic failure state. Add explicit warning when $defaultLine/GUID extraction fails for easier troubleshooting.