feat: split job history into a dedicated sidebar tab (#8957)

## Summary

Move queue job history into a dedicated sidebar tab (gated by `Comfy.Queue.QPOV2`) and remove mixed job-history UI from the Assets sidebar so assets and job controls are separated.

## Changes

- **What**:
  - Added `JobHistorySidebarTab` with reusable job UI primitives: `JobFilterTabs`, `JobFilterActions`, `JobAssetsList`, and shared `JobHistoryActionsMenu`.
  - Added reactive `job-history` tab registration in `sidebarTabStore`; prepends above Assets when `Comfy.Queue.QPOV2` is enabled and unregisters cleanly when disabled.
  - Added debounced search to `useJobList` (filters by job title, metadata, and prompt id).
  - Extracted clear-history dialog logic to `useQueueClearHistoryDialog` and reused it from queue overlay and job history tab.
  - Removed active-job rendering and queue-clear controls from assets list/grid/tab views; assets sidebar now focuses on media assets only.
  - Removed the QPOV2 gate from `MediaAssetViewModeToggle` and updated queue/job localized copy.
  - Added and updated tests for queue overlay header actions, job filters, search filtering, sidebar tab registration, and assets sidebar behavior.

## Review Focus

- Verify QPOV2 toggle behavior:
  - `Docked Job History` menu action toggles `Comfy.Queue.QPOV2`.
  - `job-history` tab insertion/removal order and active-tab reset on removal.
- Verify behavior split between tabs:
  - Job controls (cancel/delete/view/filter/search/clear history/clear queue) live in Job History.
  - Assets sidebar loading/empty states and list/grid rendering remain correct after removing active jobs.

## Screenshots (if applicable)
<img width="670" height="707" alt="image" src="https://github.com/user-attachments/assets/3a201fcb-d104-4e95-b5fe-49c4006a30a5" />

src/components/ui/Popover.vue

@@ -15,10 +15,16 @@ defineOptions({
   inheritAttrs: false
 })
 
-defineProps<{
+const {
+  entries,
+  icon,
+  to,
+  showArrow = true
+} = defineProps<{
   entries?: MenuItem[]
   icon?: string
   to?: string | HTMLElement
+  showArrow?: boolean
 }>()
 </script>
 
@@ -39,7 +45,7 @@ defineProps<{
         v-bind="$attrs"
         class="z-1700 rounded-lg p-2 bg-base-background shadow-sm border border-border-subtle will-change-[transform,opacity] data-[state=open]:data-[side=top]:animate-slideDownAndFade data-[state=open]:data-[side=right]:animate-slideLeftAndFade data-[state=open]:data-[side=bottom]:animate-slideUpAndFade data-[state=open]:data-[side=left]:animate-slideRightAndFade"
       >
-        <slot>
+        <slot :close>
           <div class="flex flex-col p-1">
             <template v-for="item in entries ?? []" :key="item.label">
               <div
@@ -71,7 +77,10 @@ defineProps<{
             </template>
           </div>
         </slot>
-        <PopoverArrow class="fill-base-background stroke-border-subtle" />
+        <PopoverArrow
+          v-if="showArrow"
+          class="fill-base-background stroke-border-subtle"
+        />
       </PopoverContent>
     </PopoverPortal>
   </PopoverRoot>