Enforce logon presentation through domain policy

docs/architecture.md

@@ -85,7 +85,8 @@ The generic SGU credential is rendered as a dedicated branded tile instead of
 being grouped below the anonymous **Other user** tile. Machine policy assigns
 the SGU CLSID as the default provider, hides the last signed-in identity, and
 disables local-user enumeration while retaining the built-in Microsoft password
-provider and its **Other user** recovery path. It enumerates one
+provider and its **Other user** recovery path. The computer GPO also applies
+Windows' native default account picture to named Windows accounts. It enumerates one
 `CPFT_TILE_IMAGE` and places the `CPFT_LARGE_TEXT` heading immediately after it
 with `CPFS_DISPLAY_IN_SELECTED_TILE`. LogonUI owns field typography and vertical
 tile order: on Windows 10 and 11, the account-name title used by **Other user**

scripts/Set-SguDomainComputerPolicies.ps1

@@ -61,15 +61,29 @@ elseif (-not $existingLinkEnabled -and
 
 $dataCollectionKey = 'HKLM\Software\Policies\Microsoft\Windows\DataCollection'
 $powerPolicyRoot = 'HKLM\Software\Policies\Microsoft\Power\PowerSettings'
+$credentialProviderPolicyKey = 'HKLM\Software\Policies\Microsoft\Windows\System'
+$interactiveLogonPolicyKey = 'HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System'
+$accountPicturePolicyKey = 'HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer'
+$providerClassId = '{D789CFD8-5AD4-489F-9B83-7EB5D9D09335}'
 $policies = @(
-    @{ Key = $dataCollectionKey; Name = 'AllowTelemetry'; Value = 0 },
-    @{ Key = $dataCollectionKey; Name = 'DisableTelemetryOptInSettingsUx'; Value = 1 },
-    @{ Key = $dataCollectionKey; Name = 'DisableTelemetryOptInChangeNotification'; Value = 1 },
-    @{ Key = $dataCollectionKey; Name = 'DisableDiagnosticDataViewer'; Value = 1 },
-    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\OOBE'; Name = 'DisablePrivacyExperience'; Value = 1 },
-    @{ Key = 'HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System'; Name = 'EnableFirstLogonAnimation'; Value = 0 },
-    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\LocationAndSensors'; Name = 'DisableLocation'; Value = 1 },
-    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\AppPrivacy'; Name = 'LetAppsAccessLocation'; Value = 2 }
+    @{ Key = $dataCollectionKey; Name = 'AllowTelemetry'; Type = 'DWord'; Value = 0 },
+    @{ Key = $dataCollectionKey; Name = 'DisableTelemetryOptInSettingsUx'; Type = 'DWord'; Value = 1 },
+    @{ Key = $dataCollectionKey; Name = 'DisableTelemetryOptInChangeNotification'; Type = 'DWord'; Value = 1 },
+    @{ Key = $dataCollectionKey; Name = 'DisableDiagnosticDataViewer'; Type = 'DWord'; Value = 1 },
+    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\OOBE'; Name = 'DisablePrivacyExperience'; Type = 'DWord'; Value = 1 },
+    @{ Key = $interactiveLogonPolicyKey; Name = 'EnableFirstLogonAnimation'; Type = 'DWord'; Value = 0 },
+    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\LocationAndSensors'; Name = 'DisableLocation'; Type = 'DWord'; Value = 1 },
+    @{ Key = 'HKLM\Software\Policies\Microsoft\Windows\AppPrivacy'; Name = 'LetAppsAccessLocation'; Type = 'DWord'; Value = 2 },
+
+    # Enrollment selects the provider before domain join; this computer GPO
+    # becomes the authoritative, self-healing configuration afterwards.
+    @{ Key = $credentialProviderPolicyKey; Name = 'DefaultCredentialProvider'; Type = 'String'; Value = $providerClassId },
+    @{ Key = $credentialProviderPolicyKey; Name = 'EnumerateLocalUsers'; Type = 'DWord'; Value = 0 },
+    @{ Key = $interactiveLogonPolicyKey; Name = 'DontDisplayLastUserName'; Type = 'DWord'; Value = 1 },
+
+    # Use Windows' native default account image for named user tiles. LogonUI
+    # retains ownership of the anonymous Other user tile and its circular mask.
+    @{ Key = $accountPicturePolicyKey; Name = 'UseDefaultTile'; Type = 'DWord'; Value = 1 }
 )
 
 $powerSettingIds = @(
@@ -80,8 +94,8 @@ $powerSettingIds = @(
 )
 foreach ($settingId in $powerSettingIds) {
     $settingKey = "$powerPolicyRoot\$settingId"
-    $policies += @{ Key = $settingKey; Name = 'ACSettingIndex'; Value = 0 }
-    $policies += @{ Key = $settingKey; Name = 'DCSettingIndex'; Value = 0 }
+    $policies += @{ Key = $settingKey; Name = 'ACSettingIndex'; Type = 'DWord'; Value = 0 }
+    $policies += @{ Key = $settingKey; Name = 'DCSettingIndex'; Type = 'DWord'; Value = 0 }
 }
 
 foreach ($policy in $policies) {
@@ -92,7 +106,7 @@ foreach ($policy in $policies) {
             -Server $DomainController `
             -Key $policy.Key `
             -ValueName $policy.Name `
-            -Type DWord `
+            -Type $policy.Type `
             -Value $policy.Value | Out-Null
     }
 }
@@ -105,7 +119,7 @@ foreach ($policy in $policies) {
         -Server $DomainController `
         -Key $policy.Key `
         -ValueName $policy.Name
-    $configuredPolicies[$policy.Name + '@' + $policy.Key] = [int]$configured.Value
+    $configuredPolicies[$policy.Name + '@' + $policy.Key] = $configured.Value
 }
 $link = @(Get-GPInheritance -Target $TargetOuDn -Domain $domainName -Server $DomainController).GpoLinks |
     Where-Object DisplayName -eq $GpoName |

scripts/Set-SguDomainUserPolicies.ps1

@@ -10,6 +10,7 @@ $ErrorActionPreference = 'Stop'
 $policyKey = 'HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System'
 $policyValueName = 'DisableLockWorkstation'
 $desktopPolicyKey = 'HKCU\Software\Policies\Microsoft\Windows\Control Panel\Desktop'
+$themeKey = 'HKCU\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize'
 
 $identity = [Security.Principal.WindowsIdentity]::GetCurrent()
 $principal = [Security.Principal.WindowsPrincipal]::new($identity)
@@ -83,6 +84,19 @@ if ($PSCmdlet.ShouldProcess($GpoName, 'Prevent SGU users from manually locking w
         -Type String `
         -Value '0' | Out-Null
 
+    # Apply the native Windows dark theme at user logon. Both values are required:
+    # one controls the shell and the other controls supported applications.
+    foreach ($themeValueName in 'AppsUseLightTheme', 'SystemUsesLightTheme') {
+        Set-GPRegistryValue `
+            -Name $GpoName `
+            -Domain $domainName `
+            -Server $DomainController `
+            -Key $themeKey `
+            -ValueName $themeValueName `
+            -Type DWord `
+            -Value 0 | Out-Null
+    }
+
     if ($WallpaperPath) {
         Set-GPRegistryValue `
             -Name $GpoName `
@@ -115,6 +129,18 @@ $screenSaverValue = Get-GPRegistryValue `
     -Server $DomainController `
     -Key $desktopPolicyKey `
     -ValueName 'ScreenSaveActive'
+$appsThemeValue = Get-GPRegistryValue `
+    -Name $GpoName `
+    -Domain $domainName `
+    -Server $DomainController `
+    -Key $themeKey `
+    -ValueName 'AppsUseLightTheme'
+$systemThemeValue = Get-GPRegistryValue `
+    -Name $GpoName `
+    -Domain $domainName `
+    -Server $DomainController `
+    -Key $themeKey `
+    -ValueName 'SystemUsesLightTheme'
 $link = @(Get-GPInheritance -Target $TargetOuDn -Domain $domainName -Server $DomainController).GpoLinks |
     Where-Object DisplayName -eq $GpoName |
     Select-Object -First 1
@@ -138,5 +164,6 @@ if ($WallpaperPath) {
     LinkEnabled = [bool]$linkEnabled
     DisableLockWorkstation = [int]$configuredValue.Value
     ScreenSaverDisabled = [string]$screenSaverValue.Value -eq '0'
+    DarkMode = ([int]$appsThemeValue.Value -eq 0) -and ([int]$systemThemeValue.Value -eq 0)
     Wallpaper = $configuredWallpaper
 }