[backport cloud/1.36] [feat] Add async model upload with WebSocket progress tracking (#7887)

Backport of #7746 to `cloud/1.36`

Automatically created by backport workflow.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7887-backport-cloud-1-36-feat-Add-async-model-upload-with-WebSocket-progress-tracking-2e26d73d365081c4a060e6e88f33016d)
by [Unito](https://www.unito.io)

Co-authored-by: Luke Mino-Altherr <luke@comfy.org>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: GitHub Action <action@github.com>

src/platform/assets/components/AssetBrowserModal.vue

@@ -83,6 +83,7 @@ import { useModelUpload } from '@/platform/assets/composables/useModelUpload'
 import type { AssetItem } from '@/platform/assets/schemas/assetSchema'
 import { assetService } from '@/platform/assets/services/assetService'
 import { formatCategoryLabel } from '@/platform/assets/utils/categoryLabel'
+import { useAssetDownloadStore } from '@/stores/assetDownloadStore'
 import { useModelToNodeStore } from '@/stores/modelToNodeStore'
 import { OnCloseKey } from '@/types/widgetTypes'
 
@@ -132,6 +133,17 @@ watch(
   { immediate: true }
 )
 
+const assetDownloadStore = useAssetDownloadStore()
+
+watch(
+  () => assetDownloadStore.hasActiveDownloads,
+  async (currentlyActive, previouslyActive) => {
+    if (previouslyActive && !currentlyActive) {
+      await execute()
+    }
+  }
+)
+
 const {
   searchQuery,
   selectedCategory,