fix(branding): guard reg unload, set ErrorAction in libs, accent field rename, test hive unload + assertions

windows/tests/Branding.Tests.ps1

@@ -38,6 +38,7 @@ Describe 'Branding layer writers' {
         $k.Manufacturer | Should -Be 'SilverLABS'
         $k.Model        | Should -Be 'SilverMetal Windows'
         $k.SupportURL   | Should -Be 'https://silverlabs.uk'
+        $k.SupportHours | Should -Be '24/7 community + paid SLA'
         $k.Logo         | Should -Be 'C:\Windows\System32\oemlogo.bmp'
     }
 
@@ -58,6 +59,7 @@ Describe 'Branding layer writers' {
         $k = Get-ItemProperty "$script:sw\Policies\Microsoft\FVE"
         $k.UseCustomRecoveryMessage | Should -Be 1
         $k.RecoveryMessage          | Should -Be 'SilverMetal Windows. Locked out? silverlabs.uk'
+        $k.RecoveryUrl              | Should -Be 'https://silverlabs.uk'
     }
 }
 
@@ -70,6 +72,7 @@ Describe 'Apply-Branding -Mode Offline' {
         foreach ($h in @("$script:mount\Windows\System32\config\SOFTWARE","$script:mount\Users\Default\NTUSER.DAT")) {
             reg load 'HKLM\SM_SEED' (New-Item -ItemType File -Force $h | Select-Object -Expand FullName) 2>$null | Out-Null
         }
+        & reg unload 'HKLM\SM_SEED' 2>$null | Out-Null
         # The above seed is best-effort; if reg can't init an empty file, the apply
         # script creates the hives via reg load of the path it expects.
     }