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/locales/en/main.json

@@ -814,6 +814,9 @@
       "activeJobs": "{count} active job | {count} active jobs",
       "activeJobsShort": "{count} active | {count} active",
       "activeJobsSuffix": "active jobs",
+      "runningJobsLabel": "{count} running",
+      "queuedJobsLabel": "{count} queued",
+      "runningQueuedSummary": "{running}, {queued}",
       "jobQueue": "Job Queue",
       "expandCollapsedQueue": "Expand job queue",
       "viewJobHistory": "View active jobs (right-click to clear queue)",