fix: clear draft on workflow close to prevent stale state on reopen (#8854)

## Summary

Clear the workflow draft from localStorage when any workflow tab is
closed, preventing stale cached state from being served when the
workflow is re-opened.

## Changes

- **What**: `closeWorkflow()` in `workflowStore.ts` now calls
`removeDraft()` for all workflows, not just temporary ones.
`closeWorkflow()` in `workflowService.ts` removes the draft before
switching tabs, preventing `beforeLoadNewGraph()` from re-saving it.

## Review Focus

- Draft is removed before the tab switch in
`workflowService.closeWorkflow()` to prevent `beforeLoadNewGraph()` from
re-saving it during the switch
- Crash recovery is preserved: drafts are only cleared on explicit
close, not on unload/crash
- Tab restore on restart is unaffected: drafts for intentionally-open
tabs are saved on graph change events, not on close

Fixes #8778
Fixes https://github.com/Comfy-Org/ComfyUI/issues/12323

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8854-fix-clear-draft-on-workflow-close-to-prevent-stale-state-on-reopen-3066d73d365081a2a633c9b352d0b0d1)
by [Unito](https://www.unito.io)

src/platform/workflow/core/services/workflowService.ts

@@ -215,6 +215,8 @@ export const useWorkflowService = () => {
       }
     }
 
+    workflowDraftStore.removeDraft(workflow.path)
+
     // If this is the last workflow, create a new default temporary workflow
     if (workflowStore.openWorkflows.length === 1) {
       await loadDefaultWorkflow()

src/platform/workflow/management/stores/workflowStore.test.ts

@@ -12,6 +12,7 @@ import {
   useWorkflowBookmarkStore,
   useWorkflowStore
 } from '@/platform/workflow/management/stores/workflowStore'
+import { useWorkflowDraftStore } from '@/platform/workflow/persistence/stores/workflowDraftStore'
 import { api } from '@/scripts/api'
 import { app as comfyApp } from '@/scripts/app'
 import { defaultGraph, defaultGraphJSON } from '@/scripts/defaultGraph'
@@ -911,4 +912,41 @@ describe('useWorkflowStore', () => {
       expect(mostRecent).toBeNull()
     })
   })
+
+  describe('closeWorkflow draft cleanup', () => {
+    it('should remove draft for persisted workflows on close', async () => {
+      const draftStore = useWorkflowDraftStore()
+      await syncRemoteWorkflows(['a.json'])
+      const workflow = store.getWorkflowByPath('workflows/a.json')!
+
+      draftStore.saveDraft('workflows/a.json', {
+        data: '{"dirty":true}',
+        updatedAt: Date.now(),
+        name: 'a.json',
+        isTemporary: false
+      })
+      expect(draftStore.getDraft('workflows/a.json')).toBeDefined()
+
+      await store.closeWorkflow(workflow)
+
+      expect(draftStore.getDraft('workflows/a.json')).toBeUndefined()
+    })
+
+    it('should remove draft for temporary workflows on close', async () => {
+      const draftStore = useWorkflowDraftStore()
+      const workflow = store.createTemporary('temp.json')
+
+      draftStore.saveDraft(workflow.path, {
+        data: '{"dirty":true}',
+        updatedAt: Date.now(),
+        name: 'temp.json',
+        isTemporary: true
+      })
+      expect(draftStore.getDraft(workflow.path)).toBeDefined()
+
+      await store.closeWorkflow(workflow)
+
+      expect(draftStore.getDraft(workflow.path)).toBeUndefined()
+    })
+  })
 })

src/platform/workflow/management/stores/workflowStore.ts

@@ -320,11 +320,9 @@ export const useWorkflowStore = defineStore('workflow', () => {
     openWorkflowPaths.value = openWorkflowPaths.value.filter(
       (path) => path !== workflow.path
     )
+    useWorkflowDraftStore().removeDraft(workflow.path)
     if (workflow.isTemporary) {
-      // Clear thumbnail when temporary workflow is closed
       clearThumbnail(workflow.key)
-      // Clear draft when unsaved workflow tab is closed
-      useWorkflowDraftStore().removeDraft(workflow.path)
       delete workflowLookup.value[workflow.path]
     } else {
       workflow.unload()