Add contact sheet to recordings associated files

common/src/main/java/ctbrec/recorder/postprocessing/CreateContactSheet.java

@@ -89,6 +89,7 @@ public class CreateContactSheet extends AbstractPlaceholderAwarePostProcessor {
             mergeLogStream.flush();
         }
         if (exitCode != 1) {
+            rec.getAssociatedFiles().add(output.getCanonicalPath());
             if (ffmpegLog.exists()) {
                 Files.delete(ffmpegLog.toPath());
             }