fix: prevent showing outputs in app mode when no output nodes configured (#9625)

## Summary

After a user runs the workflow once in graph mode, switching to app mode
with no app built, incorrectly showed the app mode outputs view instead
of the intro screen

## Changes

- **What**: don't try and select outputs if no outputs & filter out all
outputs when nothing chosen

src/renderer/extensions/linearMode/useOutputHistory.ts

@@ -65,7 +65,7 @@ export function useOutputHistory(): {
 
   function filterByOutputNodes(items: ResultItemImpl[]): ResultItemImpl[] {
     const nodeIds = appModeStore.selectedOutputs
-    if (!nodeIds.length) return items
+    if (!nodeIds.length) return []
     return items.filter((r) =>
       nodeIds.some((id) => String(id) === String(r.nodeId))
     )