Address PR feedback for OpenCode integration

ui/src/components/NewAgentDialog.tsx

@@ -58,6 +58,8 @@ export function NewAgentDialog() {
   const {
     data: adapterModels,
     error: adapterModelsError,
+    isLoading: adapterModelsLoading,
+    isFetching: adapterModelsFetching,
   } = useQuery({
     queryKey:
       selectedCompanyId
@@ -126,6 +128,10 @@ export function NewAgentDialog() {
         );
         return;
       }
+      if (adapterModelsLoading || adapterModelsFetching) {
+        setFormError("OpenCode models are still loading. Please wait and try again.");
+        return;
+      }
       const discovered = adapterModels ?? [];
       if (!discovered.some((entry) => entry.id === selectedModel)) {
         setFormError(