Fix -Frames negative range calculation to extract last N frames correctly (off-by-one error), add validation to reject invalid '-%' and '-0' formats with exit code 1, change '%' alone to extract single last frame instead of range, remove duplicate last frame from PNG sequence concat list, update Get-LastFrame.ps1 and Get-Frame.ps1 to clamp out-of-range frame indices instead of erroring and improve error messages with inline stderr output, add -y flag and -- separator to ffprobe calls, replace deprecated

Create-Scenes.ps1

@@ -161,6 +161,7 @@ function Get-SceneList {
             Frames     = $end - $start + 1
             StartTime  = [Math]::Round($start / $Info.Fps, 3)
             EndTime    = [Math]::Round($end / $Info.Fps, 3)
+            TotalTime  = [Math]::Round(($end - $start + 1) / $Info.Fps, 3)
             Suffix     = Format-SceneSuffix -Template $Template -Number ($i + 1)
         }
     }