refactor: unify DropdownItem with AssetDropdownItem

- Create AssetDropdownItem in platform/assets/types

- Create toAssetDropdownItem() transform utility

- Remove deprecated DropdownItem, SelectedKey aliases

- Rename mediaSrc to previewUrl, remove unused metadata field

- Import types directly from source, remove re-exports

Amp-Thread-ID: https://ampcode.com/threads/T-019c10b4-cabd-779d-a787-1ebf5dc8a067
Co-authored-by: Amp <amp@ampcode.com>

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

@@ -1,9 +1,10 @@
 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 type { AssetDropdownItem } from '@/platform/assets/types/assetDropdownTypes'
+import { toAssetDropdownItem } from '@/platform/assets/utils/assetDropdownUtils'
+import { isCloud } from '@/platform/distribution/types'
 import { useAssetsStore } from '@/stores/assetsStore'
 import { useModelToNodeStore } from '@/stores/modelToNodeStore'
 
@@ -47,15 +48,8 @@ export function useAssetWidgetData(
       return resolvedType ? (assetsStore.getError(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: ''
-      }))
+    const dropdownItems = computed<AssetDropdownItem[]>(() => {
+      return (assets.value ?? []).map(toAssetDropdownItem)
     })
 
     watch(