fix(offline): skip the NewGame friend fetch offline

NewGame's onMount fetched the friend list (gateway.friendsList) for a non-guest;
offline the transport kill switch refuses it, so it toasted on entering the New
Game screen (the local game still created fine). The friends section is hidden
offline anyway — skip the fetch when offline.

ui/src/screens/NewGame.svelte

@@ -112,7 +112,9 @@
   );
 
   onMount(async () => {
-    if (guest) return;
+    // Offline mode offers only the local vs_ai flow (the friends section is hidden), and the network
+    // is off, so skip the friend fetch — it would be refused by the transport and toast an error.
+    if (guest || offlineMode.active) return;
     try {
       friends = await gateway.friendsList();
     } catch (e) {