Backend and webui fixes (#11309)

* Ensure that items without end times are set to not have a snapshot

* Save full frame if no frame is currently saved

* Webui fixes

* Cleanup

web/src/components/player/dynamic/DynamicVideoPlayer.tsx

@@ -204,8 +204,8 @@ export default function DynamicVideoPlayer({
       />
       <PreviewPlayer
         className={cn(
-          isScrubbing || isLoading ? "visible" : "hidden",
           className,
+          isScrubbing || isLoading ? "visible" : "hidden",
         )}
         camera={camera}
         timeRange={timeRange}