Speed up runspace and tab initialization (#4793)

* Add startup performance tracing

* Lazy initialize non-default tabs

* Render install app entries incrementally

* Defer and cache toggle status checks

* Clean up runspace invocation ownership

* Defer GUI runspace pool startup

* Defer status taskbar asset rendering

* Record final speed verification

* Fix deferred install render timer callback

* Add dispatcher smoke coverage for install rendering

* Replace install render timer with dispatcher callbacks

* Gate performance tracing behind compile switch

* Clean up analyzer warnings in speed changes

* Speed up runspace and tab initialization

functions/private/Invoke-WinUtilAssets.ps1

@@ -5,6 +5,17 @@ function Invoke-WinUtilAssets {
       [switch]$render
   )
 
+  if ($render -and $null -ne $sync) {
+      if ($null -eq $sync.RenderedAssetCache) {
+          $sync.RenderedAssetCache = @{}
+      }
+
+      $cacheKey = "$(([string]$type).ToLowerInvariant())|$Size"
+      if ($sync.RenderedAssetCache.ContainsKey($cacheKey)) {
+          return $sync.RenderedAssetCache[$cacheKey]
+      }
+  }
+
   # Create the Viewbox and set its size
   $LogoViewbox = New-Object Windows.Controls.Viewbox
   $LogoViewbox.Width = $Size
@@ -191,6 +202,13 @@ C 21.36,47.14 28.67,50.71 30.01,52.63
       $bitmapImage.StreamSource = $imageStream
       $bitmapImage.CacheOption = [Windows.Media.Imaging.BitmapCacheOption]::OnLoad
       $bitmapImage.EndInit()
+      if ($bitmapImage.CanFreeze) {
+          $bitmapImage.Freeze()
+      }
+
+      if ($null -ne $sync -and $sync.ContainsKey("RenderedAssetCache")) {
+          $sync.RenderedAssetCache[$cacheKey] = $bitmapImage
+      }
 
       return $bitmapImage
   } else {