SDL fallback, partition fix, lz4 remote streaming, delay-oobe-run

SDL display:
- try SDL, auto-fallback to headless if it fails (no crash)
- SDL_VIDEODRIVER=x11 to avoid wayland socket path issues
- suppress XDG_RUNTIME_DIR warnings

Disk copy:
- zap-all before writing to clear old partition tables
- delete recovery partition (4) before resizing partition 3
- use parted resizepart (preserves partition GUID for BCD)
- remote: nix-shell for sgdisk/parted/ntfsresize on target
- remote: lz4 compression for faster streaming
- remote: pv progress bar with disk size
- -y/--yes flag to skip confirmation prompt

Generalize:
- delay-oobe-run=true defers OOBE + activation to real hardware
- clean cached Autounattend from Windows\Panther before sysprep
- taskkill sysprep.exe on first login (CopyProfile artifact)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/images/windows/templates/generalize.nix

@@ -53,6 +53,12 @@ in
     reg add "HKCU\Control Panel\Desktop" /v WallpaperStyle /t REG_SZ /d "0" /f
     ''}
 
+    :: Kill sysprep if it was triggered via CopyProfile'd startup entries
+    taskkill /f /im sysprep.exe 2>nul
+    :: Clean any leftover RunOnce/Run entries from audit phase
+    reg delete "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce" /v "vmixAudit" /f 2>nul
+    reg delete "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "vmixAudit" /f 2>nul
+
     :: Remove Edge AppxPackage for current user (runs in user context during OOBE)
     :: The app is already removed on one of the templates but a ghost appx entry remains that can only be deleted at the user level
     powershell -Command "Get-AppxPackage *MicrosoftEdge* | Remove-AppxPackage -ErrorAction SilentlyContinue"
@@ -148,7 +154,7 @@ in
     </unattend>
   '';
 in {
-  name = if delayOobeRun then "sealed" else "generalize";
+  name = if delayOobeRun then "generalize-delay-oobe" else "generalize";
   uploads = [
     { source = oobeXml; dest = "/oobe-unattend.xml"; }
     { source = postOobeScript; dest = "/post-oobe.cmd"; }
@@ -158,6 +164,10 @@ in {
   # generalize: sysprep + reboot into OOBE in the same QEMU session
   auditScript = ''
     @echo off
+    :: Remove cached Autounattend from initial install (contains Audit Mode reseal)
+    del /q C:\Windows\Panther\unattend.xml 2>nul
+    del /q C:\Windows\Panther\Unattend\unattend.xml 2>nul
+    del /q C:\Windows\System32\Sysprep\Panther\unattend.xml 2>nul
     C:\Windows\System32\Sysprep\sysprep.exe /generalize /oobe ${if delayOobeRun then "/shutdown" else "/reboot"} /quiet /unattend:C:\oobe-unattend.xml
   '';
 }