Add error handling to emotes fetch call

Agent-Logs-Url: https://github.com/Open3DLab/mikebase/sessions/349bd27e-61d5-40d4-b4d1-0c552a78a9e2

Co-authored-by: Ganonmaster <168445+Ganonmaster@users.noreply.github.com>

src/templates/index.html

@@ -57,7 +57,10 @@
   }
 
   fetch('/json')
-    .then(function(r){ return r.json(); })
+    .then(function(r){
+      if (!r.ok) throw new Error('HTTP ' + r.status);
+      return r.json();
+    })
     .then(function(data){
       var grid = document.getElementById('grid');
       var emotes = data.emotes || [];
@@ -83,6 +86,11 @@
         card.appendChild(span);
         grid.appendChild(card);
       });
+    })
+    .catch(function(err){
+      var grid = document.getElementById('grid');
+      grid.textContent = 'Failed to load emotes: ' + err.message;
+      grid.style.color = '#f66';
     });
 })();
 </script>