fix restoring outputs in Vue nodes (persisting node outputs when switching between workflow tabs) (#5788)

## Summary

Fixed Vue node output restoration by consolidating state management
through the node output store.

## Changes

- **What**: Refactored node output cleanup and restoration logic in
`ChangeTracker` and `ComfyApp` to use centralized store methods
- **Breaking**: Removed direct manipulation of `app.nodeOutputs` in
favor of store-managed state

## Review Focus

State synchronization between `app.nodeOutputs` and `nodeOutputs.value`
during restore/reset operations, ensuring Vue reactivity is maintained.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5788-fix-restoring-outputs-in-Vue-nodes-persisting-node-outputs-when-switching-between-workfl-27a6d73d365081b39411fed7479d8ac5)
by [Unito](https://www.unito.io)

src/scripts/app.ts

@@ -1778,9 +1778,8 @@ export class ComfyApp {
    * Clean current state
    */
   clean() {
-    this.nodeOutputs = {}
-    const { revokeAllPreviews } = useNodeOutputStore()
-    revokeAllPreviews()
+    const nodeOutputStore = useNodeOutputStore()
+    nodeOutputStore.resetAllOutputsAndPreviews()
     const executionStore = useExecutionStore()
     executionStore.lastNodeErrors = null
     executionStore.lastExecutionError = null