fix: use WidgetSelectDropdown for models (#6607)

## Summary

As the commit says, the model loaders were broken in cloud if you
enabled Vue Nodes (not a thing I think user does yet).

This fixes it by configuring the `WidgetSelectDropdown` to load so the
user load models like they would load a input or output asset.

## Review Focus

Probably `useAssetWidgetData` to make sure it's idomatic.

This part of
[assetsStore](https://github.com/Comfy-Org/ComfyUI_frontend/pull/6607/files#diff-18a5914c9f12c16d9c9c3a9f6d0e203a9c00598414d3d1c8637da9ca77339d83R158-R234)
as well.

## Screenshots

<img width="1196" height="1005" alt="Screenshot 2025-11-05 at 5 34
22 PM"
src="https://github.com/user-attachments/assets/804cd3c4-3370-4667-b606-bed52fcd6278"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6607-fix-use-WidgetSelectDropdown-for-models-2a36d73d36508143b185d06d736e4af9)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>

src/renderer/extensions/vueNodes/widgets/composables/useAssetWidgetData.ts

@@ -0,0 +1,99 @@
+import { computed, toValue, watch } from 'vue'
+import type { MaybeRefOrGetter } from 'vue'
+
+import { isCloud } from '@/platform/distribution/types'
+import type { AssetItem } from '@/platform/assets/schemas/assetSchema'
+import type { DropdownItem } from '@/renderer/extensions/vueNodes/widgets/components/form/dropdown/types'
+import { useAssetsStore } from '@/stores/assetsStore'
+import { useModelToNodeStore } from '@/stores/modelToNodeStore'
+
+/**
+ * Composable for fetching and transforming asset data for Vue node widgets.
+ * Provides reactive asset data based on node type with automatic category detection.
+ * Uses store-based caching to avoid duplicate fetches across multiple instances.
+ *
+ * Cloud-only composable - returns empty data when not in cloud environment.
+ *
+ * @param nodeType - ComfyUI node type (ref, getter, or plain value). Can be undefined.
+ *   Accepts: ref('CheckpointLoaderSimple'), () => 'CheckpointLoaderSimple', or 'CheckpointLoaderSimple'
+ * @returns Reactive data including category, assets, dropdown items, loading state, and errors
+ */
+export function useAssetWidgetData(
+  nodeType: MaybeRefOrGetter<string | undefined>
+) {
+  if (isCloud) {
+    const assetsStore = useAssetsStore()
+    const modelToNodeStore = useModelToNodeStore()
+
+    const category = computed(() => {
+      const resolvedType = toValue(nodeType)
+      return resolvedType
+        ? modelToNodeStore.getCategoryForNodeType(resolvedType)
+        : undefined
+    })
+
+    const assets = computed<AssetItem[]>(() => {
+      const resolvedType = toValue(nodeType)
+      return resolvedType
+        ? (assetsStore.modelAssetsByNodeType.get(resolvedType) ?? [])
+        : []
+    })
+
+    const isLoading = computed(() => {
+      const resolvedType = toValue(nodeType)
+      return resolvedType
+        ? (assetsStore.modelLoadingByNodeType.get(resolvedType) ?? false)
+        : false
+    })
+
+    const error = computed<Error | null>(() => {
+      const resolvedType = toValue(nodeType)
+      return resolvedType
+        ? (assetsStore.modelErrorByNodeType.get(resolvedType) ?? null)
+        : null
+    })
+
+    const dropdownItems = computed<DropdownItem[]>(() => {
+      return assets.value.map((asset) => ({
+        id: asset.id,
+        name:
+          (asset.user_metadata?.filename as string | undefined) ?? asset.name,
+        label: asset.name,
+        mediaSrc: asset.preview_url ?? '',
+        metadata: ''
+      }))
+    })
+
+    watch(
+      () => toValue(nodeType),
+      async (currentNodeType) => {
+        if (!currentNodeType) {
+          return
+        }
+
+        const hasData = assetsStore.modelAssetsByNodeType.has(currentNodeType)
+
+        if (!hasData) {
+          await assetsStore.updateModelsForNodeType(currentNodeType)
+        }
+      },
+      { immediate: true }
+    )
+
+    return {
+      category,
+      assets,
+      dropdownItems,
+      isLoading,
+      error
+    }
+  }
+
+  return {
+    category: computed(() => undefined),
+    assets: computed(() => []),
+    dropdownItems: computed(() => []),
+    isLoading: computed(() => false),
+    error: computed(() => null)
+  }
+}