Clean up intermediate render files during xfade

Sources/GrowthLapse/VideoProcessor.swift

@@ -450,6 +450,11 @@ final class VideoProcessor: ObservableObject {
                     clipNumber: clipNumber,
                     totalClips: videos.count
                 )
+                if !settings.keepIntermediateClips {
+                    removeTemporaryFile(segmentURL)
+                    removeTemporaryFile(stabilizedURL)
+                    removeTemporaryFile(tempDirectory.appendingPathComponent(String(format: "clip_%04d.trf", clipNumber)))
+                }
             } else {
                 try await normalizeSourceSegment(
                     source: video.url,
@@ -808,6 +813,10 @@ final class VideoProcessor: ObservableObject {
                 throw VideoProcessingError.ffmpegFailed("Xfade Übergang \(index)", result.output)
             }
 
+            if !settings.keepIntermediateClips {
+                removeTemporaryFile(current)
+                removeTemporaryFile(next)
+            }
             current = out
             currentDuration += settings.targetClipLength - settings.transitionLength
             progress = 0.75 + (Double(index) / Double(totalSteps)) * 0.25
@@ -834,6 +843,17 @@ final class VideoProcessor: ObservableObject {
         try FileManager.default.copyItem(at: source, to: outputFile)
     }
 
+    private func removeTemporaryFile(_ url: URL) {
+        guard FileManager.default.fileExists(atPath: url.path) else {
+            return
+        }
+        do {
+            try FileManager.default.removeItem(at: url)
+        } catch {
+            appendLog("Warnung: Temporäre Datei konnte nicht gelöscht werden: \(url.lastPathComponent) (\(error.localizedDescription))")
+        }
+    }
+
     private func escapeConcatPath(_ path: String) -> String {
         path.replacingOccurrences(of: "'", with: "'\\''")
     }