Change NCNN_GPU_ID=-1 handling in Clone-Image.ps1 to omit upscayl-bin -g flag instead of passing -1 (which the tested build rejects), update documentation across Clone-Image.md, SKILL.md, README.md and index.md to clarify -1 means CPU for rife-ncnn-vulkan but default device for upscayl-bin, wrap Get-SrtContent calls in Create-FullSubtitle.ps1 with @() array operator to ensure Count property exists when parsing returns single entry, fix Get-FramesRange.ps1 output directory resolution to use Resolve-Path before

Clone-Image.ps1

@@ -33,7 +33,7 @@
     ffmpeg input, so any -Size / -LTX cover-scale-then-crop is applied to the upscaled image.
     Requires upscayl-bin.exe in PATH, the UPSCAYL_HOME environment variable pointing to the
     upscayl-bin install directory, and the NCNN_GPU_ID environment variable set to the desired
-    GPU device ID (-1 for CPU, 0/1/2/... for GPU).
+    GPU device ID (0/1/2/... for a GPU, or -1 to omit the -g flag so upscayl-bin uses its default device).
 .PARAMETER Model
     Upscayl model name (without extension) to use when -Upscale is specified. Defaults to
     '4xNomos8kSC'. The model files (<Model>.bin and <Model>.param) must exist under
@@ -328,7 +328,7 @@ if ($Upscale -gt 0) {
         exit 1
     }
     if ($gpuId -notmatch '^-?\d+$') {
-        Write-Error ('NCNN_GPU_ID must be an integer (-1 for CPU, 0+ for GPU). Current value: {0}' -f $gpuId)
+        Write-Error ('NCNN_GPU_ID must be an integer (-1 for the default device, 0+ for a GPU index). Current value: {0}' -f $gpuId)
         exit 1
     }
 
@@ -337,7 +337,8 @@ if ($Upscale -gt 0) {
     Write-Host ('Upscaling source with upscayl-bin (x{0}, model={1}, gpu={2})...' -f $Upscale, $Model, $gpuId)
     Write-Host ('  Upscayl temp file: {0}' -f $upscaledTempPath)
 
-    $upscaylArgs = @('-i', $SourcePath, '-o', $upscaledTempPath, '-s', $Upscale.ToString(), '-n', $Model, '-m', $modelsDir, '-g', $gpuId)
+    $upscaylArgs = @('-i', $SourcePath, '-o', $upscaledTempPath, '-s', $Upscale.ToString(), '-n', $Model, '-m', $modelsDir)
+    if ([int]$gpuId -ge 0) { $upscaylArgs += @('-g', $gpuId) }
     $upscaylCmdLine = '"{0}" {1}' -f $upscaylExePath, (($upscaylArgs | ForEach-Object {
         if ($_ -match '\s') { '"{0}"' -f $_ } else { $_ }
     }) -join ' ')