App mode - discard slow preview messages to prevent overwriting output image (#9261)

## Summary

Prevent latent previews received after the job/node has already finished
processing overwriting the actual output display

## Changes

- **What**: 
- updates job preview store to also track which node the preview was for
- updates linear progress tracking to store executed nodes enabling
skipping previews of these

## Review Focus

<!-- Critical design decisions or edge cases that need attention -->

<!-- If this PR fixes an issue, uncomment and update the line below -->
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## Screenshots (if applicable)

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┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9261-App-mode-discard-slow-preview-messages-to-prevent-overwriting-output-image-3136d73d3650817884c2ce2ff5993b9e)
by [Unito](https://www.unito.io)

src/scripts/app.ts

@@ -761,7 +761,7 @@ export class ComfyApp {
       const { setNodePreviewsByExecutionId, revokePreviewsByExecutionId } =
         useNodeOutputStore()
       const blobUrl = createSharedObjectUrl(blob)
-      useJobPreviewStore().setPreviewUrl(jobId, blobUrl)
+      useJobPreviewStore().setPreviewUrl(jobId, blobUrl, displayNodeId)
       // Ensure clean up if `executing` event is missed.
       revokePreviewsByExecutionId(displayNodeId)
       // Preview cleanup is handled in progress_state event to support multiple concurrent previews