Add BITS transfer priority configuration support

Introduces a new parameter to control BITS download priority across the build system and UI, allowing users to optimize transfer speeds when needed.

The feature adds a priority selector to the UI with four options (Foreground, High, Normal, Low) and propagates the selection through the build script and common modules. Priority can be set via UI, command-line parameter, or environment variable, with Normal as the default.

Updates the BITS transfer retry logic to respect the configured priority instead of hardcoding Normal priority, and fixes minor code formatting inconsistencies.

FFUDevelopment/FFUUI.Core/FFUUI.Core.Config.psm1

@@ -96,6 +96,7 @@ function Get-UIConfig {
         USBDriveList                   = @{}
         Username                       = $State.Controls.txtUsername.Text
         Threads                        = [int]$State.Controls.txtThreads.Text
+        BitsPriority                    = $State.Controls.cmbBitsPriority.SelectedItem
         MaxUSBDrives                   = [int]$State.Controls.txtMaxUSBDrives.Text
         Verbose                        = $State.Controls.chkVerbose.IsChecked
         VMHostIPAddress                = $State.Controls.txtVMHostIPAddress.Text
@@ -412,6 +413,7 @@ function Update-UIFromConfig {
     Set-UIValue -ControlName 'txtShareName' -PropertyName 'Text' -ConfigObject $ConfigContent -ConfigKey 'ShareName' -State $State
     Set-UIValue -ControlName 'txtUsername' -PropertyName 'Text' -ConfigObject $ConfigContent -ConfigKey 'Username' -State $State
     Set-UIValue -ControlName 'txtThreads' -PropertyName 'Text' -ConfigObject $ConfigContent -ConfigKey 'Threads' -State $State
+    Set-UIValue -ControlName 'cmbBitsPriority' -PropertyName 'SelectedItem' -ConfigObject $ConfigContent -ConfigKey 'BitsPriority' -State $State
     Set-UIValue -ControlName 'txtMaxUSBDrives' -PropertyName 'Text' -ConfigObject $ConfigContent -ConfigKey 'MaxUSBDrives' -State $State
     Set-UIValue -ControlName 'chkBuildUSBDriveEnable' -PropertyName 'IsChecked' -ConfigObject $ConfigContent -ConfigKey 'BuildUSBDrive' -State $State
     Set-UIValue -ControlName 'chkCompactOS' -PropertyName 'IsChecked' -ConfigObject $ConfigContent -ConfigKey 'CompactOS' -State $State
@@ -748,13 +750,14 @@ function Update-UIFromConfig {
             else {
                 $State.Controls.additionalFFUPanel.Visibility = 'Collapsed'
             }
+            }
+            catch {
+                WriteLog "LoadConfig: Error applying Additional FFU selections: $($_.Exception.Message)"
+            }
+        
+            Update-BitsPrioritySetting -State $State
+            WriteLog "LoadConfig: Configuration loading process finished."
         }
-        catch {
-            WriteLog "LoadConfig: Error applying Additional FFU selections: $($_.Exception.Message)"
-        }
-    
-        WriteLog "LoadConfig: Configuration loading process finished."
-    }
 
 function Invoke-SaveConfiguration {
     param(

FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1

@@ -152,6 +152,17 @@ function Register-EventHandlers {
             $localState.Controls.chkPromptExternalHardDiskMedia.IsChecked = $false
         })
 
+    if ($null -ne $State.Controls.cmbBitsPriority) {
+        $State.Controls.cmbBitsPriority.Add_SelectionChanged({
+                param($eventSource, $selectionChangedEventArgs)
+                $window = [System.Windows.Window]::GetWindow($eventSource)
+                if ($null -eq $window -or $null -eq $window.Tag) {
+                    return
+                }
+                Update-BitsPrioritySetting -State $window.Tag
+            })
+    }
+
     # Additional FFU Files events
     $State.Controls.chkCopyAdditionalFFUFiles.Add_Checked({
             param($eventSource, $routedEventArgs)

FFUDevelopment/FFUUI.Core/FFUUI.Core.Initialize.psm1

@@ -118,6 +118,7 @@ function Initialize-UIControls {
     $State.Controls.txtShareName = $window.FindName('txtShareName')
     $State.Controls.txtUsername = $window.FindName('txtUsername')
     $State.Controls.txtThreads = $window.FindName('txtThreads')
+    $State.Controls.cmbBitsPriority = $window.FindName('cmbBitsPriority')
     $State.Controls.txtMaxUSBDrives = $window.FindName('txtMaxUSBDrives')
     $State.Controls.chkCompactOS = $window.FindName('chkCompactOS')
     $State.Controls.chkOptimize = $window.FindName('chkOptimize')
@@ -234,6 +235,7 @@ function Initialize-UIDefaults {
     $State.Controls.txtShareName.Text = $State.Defaults.generalDefaults.ShareName
     $State.Controls.txtUsername.Text = $State.Defaults.generalDefaults.Username
     $State.Controls.txtThreads.Text = $State.Defaults.generalDefaults.Threads
+    $State.Controls.cmbBitsPriority.SelectedItem = $State.Defaults.generalDefaults.BitsPriority
     $State.Controls.txtMaxUSBDrives.Text = $State.Defaults.generalDefaults.MaxUSBDrives
     $State.Controls.chkBuildUSBDriveEnable.IsChecked = $State.Defaults.generalDefaults.BuildUSBDriveEnable
     $State.Controls.chkCompactOS.IsChecked = $State.Defaults.generalDefaults.CompactOS
@@ -263,6 +265,7 @@ function Initialize-UIDefaults {
     $State.Controls.chkPromptExternalHardDiskMedia.IsEnabled = $State.Controls.chkAllowExternalHardDiskMedia.IsChecked
     $State.Controls.chkCopyAdditionalFFUFiles.IsChecked = $State.Defaults.generalDefaults.CopyAdditionalFFUFiles
     $State.Controls.additionalFFUPanel.Visibility = if ($State.Controls.chkCopyAdditionalFFUFiles.IsChecked) { 'Visible' } else { 'Collapsed' }
+    Update-BitsPrioritySetting -State $State
 
     # Hyper-V Settings defaults from General Defaults
     Initialize-VMSwitchData -State $State

FFUDevelopment/FFUUI.Core/FFUUI.Core.Shared.psm1

@@ -220,6 +220,32 @@ function Invoke-ProgressUpdate {
     $ProgressQueue.Enqueue(@{ Identifier = $Identifier; Status = $Status })
 }
 
+function Update-BitsPrioritySetting {
+    param(
+        [Parameter(Mandatory)]
+        [pscustomobject]$State
+    )
+
+    $combo = $State.Controls.cmbBitsPriority
+    if ($null -eq $combo) {
+        WriteLog "BITS priority control not available; skipping priority update."
+        return
+    }
+
+    $selectedPriority = $combo.SelectedItem
+    if ([string]::IsNullOrWhiteSpace($selectedPriority)) {
+        $selectedPriority = 'Normal'
+    }
+
+    try {
+        Set-BitsTransferPriority -Priority $selectedPriority
+        WriteLog "BITS transfer priority set to $selectedPriority."
+    }
+    catch {
+        WriteLog "Failed to set BITS transfer priority: $($_.Exception.Message)"
+    }
+}
+
 # Add a function to create a sortable list view
 function Add-SortableColumn {
     param(

FFUDevelopment/FFUUI.Core/FFUUI.Core.psm1

@@ -117,6 +117,7 @@ function Get-GeneralDefaults {
         ShareName                      = "FFUCaptureShare"
         Username                       = "ffu_user"
         Threads                        = 5
+        BitsPriority                   = 'Normal'
         MaxUSBDrives                   = 5
         BuildUSBDriveEnable            = $false
         CompactOS                      = $true