Fix jobs dashboard showing misleading completion message

The dashboard was showing "All jobs completed successfully" whenever
there were no failed tasks, even if there were pending or in-progress
jobs. Now shows:
- "All jobs completed" only when pending=0 and in_progress=0
- "Jobs are processing. No failures yet." when jobs are in queue

frontend/src/pages/AdminJobsPage.tsx

@@ -192,9 +192,9 @@ function AdminJobsPage() {
 
             {totalJobs === 0 ? (
               <p className="empty-message">No cache jobs yet. Jobs are created when packages are downloaded through the PyPI proxy.</p>
-            ) : failedTasks.length === 0 ? (
+            ) : failedTasks.length === 0 && cacheStatus?.pending === 0 && cacheStatus?.in_progress === 0 ? (
               <p className="success-text">All jobs completed successfully.</p>
-            ) : (
+            ) : failedTasks.length > 0 ? (
               <>
                 <h3>Failed Tasks</h3>
                 <table className="jobs-table">
@@ -236,6 +236,8 @@ function AdminJobsPage() {
                   </tbody>
                 </table>
               </>
+            ) : (
+              <p className="empty-message">Jobs are processing. No failures yet.</p>
             )}
           </>
         )}