fix: move queue assets action into filter controls (#8926)

## Summary

Move the queue overlay "Show assets" action into the filter controls as
an icon button, so the action is available inline with other list
controls while keeping existing behavior.

## Changes

- **What**:
- Remove the full-width "Show assets" button from
`QueueOverlayExpanded`.
- Add a secondary icon button in `JobFiltersBar` with tooltip +
aria-label and emit `showAssets` on click.
- Wire `showAssets` from `JobFiltersBar` through `QueueOverlayExpanded`
to the existing handler.
- Add `JobFiltersBar` unit coverage to verify `showAssets` is emitted
when the icon button is clicked.

## Review Focus

- Verify the icon button placement in the filter row is sensible and
discoverable.
- Verify clicking the new button opens the assets panel as before.
- Verify tooltip and accessibility label copy are correct.

## Screenshots (if applicable)
Design:
https://www.figma.com/design/LVilZgHGk5RwWOkVN6yCEK/Queue-Progress-Modal?node-id=3924-38560&m=dev
<img width="349" height="52" alt="Screenshot 2026-02-16 at 4 53 34 PM"
src="https://github.com/user-attachments/assets/347772d6-5536-457a-a65f-de251e35a0e4"
/>

src/components/queue/QueueOverlayExpanded.vue

@@ -9,23 +9,12 @@
       @clear-queued="$emit('clearQueued')"
     />
 
-    <div class="px-3">
-      <Button
-        class="w-full gap-1 justify-center"
-        variant="secondary"
-        size="sm"
-        @click="$emit('showAssets')"
-      >
-        <i class="icon-[comfy--image-ai-edit] size-4" />
-        <span>{{ t('sideToolbar.queueProgressOverlay.showAssets') }}</span>
-      </Button>
-    </div>
-
     <JobFiltersBar
       :selected-job-tab="selectedJobTab"
       :selected-workflow-filter="selectedWorkflowFilter"
       :selected-sort-mode="selectedSortMode"
       :has-failed-jobs="hasFailedJobs"
+      @show-assets="$emit('showAssets')"
       @update:selected-job-tab="$emit('update:selectedJobTab', $event)"
       @update:selected-workflow-filter="
         $emit('update:selectedWorkflowFilter', $event)
@@ -53,9 +42,7 @@
 
 <script setup lang="ts">
 import { ref } from 'vue'
-import { useI18n } from 'vue-i18n'
 
-import Button from '@/components/ui/button/Button.vue'
 import type {
   JobGroup,
   JobListItem,
@@ -94,8 +81,6 @@ const emit = defineEmits<{
   (e: 'viewItem', item: JobListItem): void
 }>()
 
-const { t } = useI18n()
-
 const currentMenuItem = ref<JobListItem | null>(null)
 const jobContextMenuRef = ref<InstanceType<typeof JobContextMenu> | null>(null)