Auto-execute first example on initial app load

- Make onMounted async to properly wait for WebR initialization
- Execute the first example automatically once WebR is ready
- Provides immediate visual feedback when app loads for the first time

This ensures users see the "Getting started" example plot immediately
when opening the application, improving the initial user experience.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: stared

src/App.vue

@@ -165,11 +165,16 @@ const fetchGitHubStars = async () => {
   }
 }
 
-onMounted(() => {
-  // Initialize WebR without auto-executing the initial code
-  void initializeWebR('')
+onMounted(async () => {
+  // Initialize WebR first
+  await initializeWebR('')
   // Fetch GitHub stars
   void fetchGitHubStars()
+  
+  // Execute the first example once WebR is ready
+  if (isReady.value && examples.length > 0) {
+    await handleExampleSelect(examples[0])
+  }
 })
 </script>