fix: localize queue overlay running and queued summary (#8919)

## Summary
- Localize QueueProgressOverlay header counts with dedicated i18n pluralization keys for running and queued jobs.
- Replace the previous aggregate active-job wording with a translated running/queued summary.

## What changed
- Updated `QueueProgressOverlay.vue` to derive `runningJobsLabel`, `queuedJobsLabel`, and `runningQueuedSummary` via `useI18n`.
- Added `QueueProgressOverlay.test.ts` coverage for expanded-header text in both active and empty queue states.
- Added new English locale keys in `src/locales/en/main.json`:
  - `runningJobsLabel`
  - `queuedJobsLabel`
  - `runningQueuedSummary`

## Testing
- `Storybook Build Status` passed.
- `Playwright Tests` were still running at the last check; merge should wait for completion.

## Notes
- Behavioral scope is limited to queue overlay header text/rendering.

Design: https://www.figma.com/design/LVilZgHGk5RwWOkVN6yCEK/Queue-Progress-Modal?node-id=3924-38560&m=dev

<img width="356" height="59" alt="Screenshot 2026-02-16 at 3 30 44 PM" src="https://github.com/user-attachments/assets/987e42bd-9e24-4e65-9158-3f96b5338199" />

src/components/queue/QueueProgressOverlay.vue

@@ -92,7 +92,7 @@ const emit = defineEmits<{
   (e: 'update:expanded', value: boolean): void
 }>()
 
-const { t } = useI18n()
+const { t, n } = useI18n()
 const queueStore = useQueueStore()
 const commandStore = useCommandStore()
 const executionStore = useExecutionStore()
@@ -126,7 +126,6 @@ const runningCount = computed(() => queueStore.runningTasks.length)
 const queuedCount = computed(() => queueStore.pendingTasks.length)
 const isExecuting = computed(() => !executionStore.isIdle)
 const hasActiveJob = computed(() => runningCount.value > 0 || isExecuting.value)
-const activeJobsCount = computed(() => runningCount.value + queuedCount.value)
 
 const overlayState = computed<OverlayState>(() => {
   if (isExpanded.value) return 'expanded'
@@ -156,11 +155,34 @@ const bottomRowClass = computed(
         : 'opacity-0 pointer-events-none'
     }`
 )
-const headerTitle = computed(() =>
-  hasActiveJob.value
-    ? `${activeJobsCount.value} ${t('sideToolbar.queueProgressOverlay.activeJobsSuffix')}`
-    : t('sideToolbar.queueProgressOverlay.jobQueue')
+const runningJobsLabel = computed(() =>
+  t('sideToolbar.queueProgressOverlay.runningJobsLabel', {
+    count: n(runningCount.value)
+  })
 )
+const queuedJobsLabel = computed(() =>
+  t('sideToolbar.queueProgressOverlay.queuedJobsLabel', {
+    count: n(queuedCount.value)
+  })
+)
+const headerTitle = computed(() => {
+  if (!hasActiveJob.value) {
+    return t('sideToolbar.queueProgressOverlay.jobQueue')
+  }
+
+  if (queuedCount.value === 0) {
+    return runningJobsLabel.value
+  }
+
+  if (runningCount.value === 0) {
+    return queuedJobsLabel.value
+  }
+
+  return t('sideToolbar.queueProgressOverlay.runningQueuedSummary', {
+    running: runningJobsLabel.value,
+    queued: queuedJobsLabel.value
+  })
+})
 
 const concurrentWorkflowCount = computed(
   () => executionStore.runningWorkflowCount