feat: inform user when save action failed

fixes #67

src/routes/EditActions.svelte

@@ -35,6 +35,7 @@
   let redoQueue: Change[] = []
 
   async function save() {
+    try {
       const port = $serialPort
       if (!port) return
       $syncStatus = "uploading"
@@ -112,8 +113,13 @@
       $deviceChords = $chords.filter(({deleted}) => !deleted).map(({actions, phrase}) => ({actions, phrase}))
       $deviceSettings = $settings.map(({value}) => value)
       $changes = []
+    } catch (e) {
+      alert(e)
+      console.error(e)
+    } finally {
       $syncStatus = "done"
     }
+  }
 </script>
 
 <button