Add viewer network statistics panel

apps/viewer/src/api.ts

@@ -11,7 +11,7 @@ export async function fetchWorldSnapshot(signal?: AbortSignal) {
 export function openWorldStream(
   afterSequence: number,
   handlers: {
-    onDelta: (delta: WorldDelta) => void;
+    onDelta: (delta: WorldDelta, rawBytes: number) => void;
     onOpen?: () => void;
     onError?: () => void;
   },
@@ -21,7 +21,10 @@ export function openWorldStream(
   stream.addEventListener("error", () => handlers.onError?.());
   stream.addEventListener("world-delta", (event) => {
     const message = event as MessageEvent<string>;
-    handlers.onDelta(JSON.parse(message.data) as WorldDelta);
+    handlers.onDelta(
+      JSON.parse(message.data) as WorldDelta,
+      new Blob([message.data]).size,
+    );
   });
   return stream;
 }