Spread nowPlayings into payload and cache

Make the client update now-playings by assigning a fresh array and
disable redundant invalidations. Adjust the websocket message shape so
the fields arrive at the top level for the client to consume.

apps/web/src/pages/home/feed/Feed.tsx

···
       }
 
       const message = JSON.parse(event.data);
-      queryClient.setQueryData(["now-playings"], () => message.nowPlayings);
+      queryClient.setQueryData(["now-playings"], () => [
+        ...message.nowPlayings,
+      ]);
       queryClient.setQueryData(
         ["scrobblesChart"],
         () => message.scrobblesChart,
···
       await queryClient.invalidateQueries({
         queryKey: ["infiniteFeed", feedUri],
       });
-      await queryClient.invalidateQueries({ queryKey: ["now-playings"] });
-      await queryClient.invalidateQueries({ queryKey: ["scrobblesChart"] });
+      // await queryClient.invalidateQueries({ queryKey: ["now-playings"] });
+      // await queryClient.invalidateQueries({ queryKey: ["scrobblesChart"] });
     };
 
     return () => {

apps/ws/src/main.ts

···
         if (channels.has(collection) && socket.readyState === WebSocket.OPEN) {
           socket.send(
             JSON.stringify({
-              nowPlayings,
+              ...nowPlayings,
               scrobbles,
               scrobblesChart,
               actorScrobbles,