feat: show active jobs label in top menu (#8169)

Replace the top-menu queue history icon with a localized “N active”
label so active jobs are visible at a glance.

Requested as part of the new
[designs](https://www.figma.com/design/LVilZgHGk5RwWOkVN6yCEK/Queue-Progress-Modal?node-id=3381-6181&m=dev).

I checked all failing snapshots and they are all expected (1 flaky).

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8169-feat-show-active-jobs-label-in-top-menu-2ee6d73d3650812cbf0cda389395c563)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

src/stores/queueStore.ts

@@ -493,6 +493,9 @@ export const useQueueStore = defineStore('queue', () => {
   )
 
   const hasPendingTasks = computed<boolean>(() => pendingTasks.value.length > 0)
+  const activeJobsCount = computed(
+    () => pendingTasks.value.length + runningTasks.value.length
+  )
 
   const update = async () => {
     isLoading.value = true
@@ -572,6 +575,7 @@ export const useQueueStore = defineStore('queue', () => {
     flatTasks,
     lastHistoryQueueIndex,
     hasPendingTasks,
+    activeJobsCount,
 
     update,
     clear,