Add expandable output stacks to assets list view (#8283)

Add expandable output stacks to the assets list view.

Monolith ver. of https://github.com/Comfy-Org/ComfyUI_frontend/pull/8298
and its children

List view currently collapses multi-output jobs into a single row, which
makes sibling outputs easy to miss and causes selection/zoom behavior to
drift once items are expanded elsewhere. This change adds a stack toggle
to list rows, expands child outputs derived from job data, and keeps
list-view selection and gallery navigation aligned with the expanded
list. Output mapping and “load full outputs” checks are centralized so
folder view and stacks share the same helper, and job-detail parsing now
yields previewable outputs for the list view. Asset actions now prefer
metadata prompt IDs to support the composite IDs used by stacked
outputs.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8283-Add-expandable-output-stacks-to-assets-list-view-2f16d73d365081a99fc6f1519ac2e57c)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Johnpaul Chiwetelu <49923152+Myestery@users.noreply.github.com>

src/components/sidebar/tabs/AssetsSidebarListView.vue

@@ -40,7 +40,7 @@
     </div>
 
     <div
-      v-if="assets.length"
+      v-if="assetItems.length"
       :class="cn('px-2', activeJobItems.length && 'mt-2')"
     >
       <div
@@ -79,7 +79,12 @@
                 type: getMediaTypeFromFilename(item.asset.name)
               })
             "
-            :class="getAssetCardClass(isSelected(item.asset.id))"
+            :class="
+              cn(
+                getAssetCardClass(isSelected(item.asset.id)),
+                item.isChild && 'pl-6'
+              )
+            "
             :preview-url="item.asset.preview_url"
             :preview-alt="item.asset.name"
             :icon-name="
@@ -87,10 +92,14 @@
             "
             :primary-text="getAssetPrimaryText(item.asset)"
             :secondary-text="getAssetSecondaryText(item.asset)"
+            :stack-count="getStackCount(item.asset)"
+            :stack-indicator-label="t('mediaAsset.actions.seeMoreOutputs')"
+            :stack-expanded="isStackExpanded(item.asset)"
             @mouseenter="onAssetEnter(item.asset.id)"
             @mouseleave="onAssetLeave(item.asset.id)"
             @contextmenu.prevent.stop="emit('context-menu', $event, item.asset)"
-            @click.stop="emit('select-asset', item.asset)"
+            @click.stop="emit('select-asset', item.asset, selectableAssets)"
+            @stack-toggle="void toggleStack(item.asset)"
           >
             <template v-if="hoveredAssetId === item.asset.id" #actions>
               <Button
@@ -120,6 +129,7 @@ import { useJobActions } from '@/composables/queue/useJobActions'
 import type { JobListItem } from '@/composables/queue/useJobList'
 import { useJobList } from '@/composables/queue/useJobList'
 import AssetsListItem from '@/platform/assets/components/AssetsListItem.vue'
+import type { OutputStackListItem } from '@/platform/assets/composables/useOutputStacks'
 import { getOutputAssetMetadata } from '@/platform/assets/schemas/assetMetadataSchema'
 import type { AssetItem } from '@/platform/assets/schemas/assetSchema'
 import { iconForMediaType } from '@/platform/assets/utils/mediaIconUtil'
@@ -136,19 +146,25 @@ import { cn } from '@/utils/tailwindUtil'
 import { useSettingStore } from '@/platform/settings/settingStore'
 
 const {
-  assets,
+  assetItems,
+  selectableAssets,
   isSelected,
+  isStackExpanded,
+  toggleStack,
   assetType = 'output'
 } = defineProps<{
-  assets: AssetItem[]
+  assetItems: OutputStackListItem[]
+  selectableAssets: AssetItem[]
   isSelected: (assetId: string) => boolean
+  isStackExpanded: (asset: AssetItem) => boolean
+  toggleStack: (asset: AssetItem) => Promise<void>
   assetType?: 'input' | 'output'
 }>()
 
 const assetsStore = useAssetsStore()
 
 const emit = defineEmits<{
-  (e: 'select-asset', asset: AssetItem): void
+  (e: 'select-asset', asset: AssetItem, assets?: AssetItem[]): void
   (e: 'context-menu', event: MouseEvent, asset: AssetItem): void
   (e: 'approach-end'): void
 }>()
@@ -162,9 +178,6 @@ const isQueuePanelV2Enabled = computed(() =>
 )
 const hoveredJobId = ref<string | null>(null)
 const hoveredAssetId = ref<string | null>(null)
-
-type AssetListItem = { key: string; asset: AssetItem }
-
 const activeJobItems = computed(() =>
   jobItems.value.filter((item) => isActiveJobState(item.state))
 )
@@ -176,13 +189,6 @@ const hoveredJob = computed(() =>
 )
 const { cancelAction, canCancelJob, runCancelJob } = useJobActions(hoveredJob)
 
-const assetItems = computed<AssetListItem[]>(() =>
-  assets.map((asset) => ({
-    key: `asset-${asset.id}`,
-    asset
-  }))
-)
-
 const listGridStyle = {
   display: 'grid',
   gridTemplateColumns: 'minmax(0, 1fr)',
@@ -212,6 +218,19 @@ function getAssetSecondaryText(asset: AssetItem): string {
   return ''
 }
 
+function getStackCount(asset: AssetItem): number | undefined {
+  const metadata = getOutputAssetMetadata(asset.user_metadata)
+  if (typeof metadata?.outputCount === 'number') {
+    return metadata.outputCount
+  }
+
+  if (Array.isArray(metadata?.allOutputs)) {
+    return metadata.allOutputs.length
+  }
+
+  return undefined
+}
+
 function getAssetCardClass(selected: boolean): string {
   return cn(
     'w-full text-text-primary transition-colors hover:bg-secondary-background-hover',