fix(ui): Remove Cleanup Stale button from Workers page

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cannaiq/src/pages/WorkersDashboard.tsx

@@ -292,16 +292,6 @@ export function WorkersDashboard() {
     }
   }, []);
 
-  // Cleanup stale workers
-  const handleCleanupStale = async () => {
-    try {
-      await api.post('/api/worker-registry/cleanup', { stale_threshold_minutes: 2 });
-      fetchData();
-    } catch (err: any) {
-      console.error('Cleanup error:', err);
-    }
-  };
-
   // Remove a single worker
   const handleRemoveWorker = async (workerId: string) => {
     if (!confirm('Remove this worker from the registry?')) return;
@@ -364,15 +354,6 @@ export function WorkersDashboard() {
               {workers.length} registered workers ({busyWorkers.length} busy, {idleWorkers.length} idle)
             </p>
           </div>
-          <div className="flex items-center gap-2">
-            <button
-              onClick={handleCleanupStale}
-              className="flex items-center gap-2 px-4 py-2 bg-gray-100 text-gray-700 rounded-lg hover:bg-gray-200 transition-colors"
-              title="Mark stale workers (no heartbeat > 2 min) as offline"
-            >
-              <Trash2 className="w-4 h-4" />
-              Cleanup Stale
-            </button>
           <button
             onClick={() => fetchData()}
             className="flex items-center gap-2 px-4 py-2 bg-emerald-600 text-white rounded-lg hover:bg-emerald-700 transition-colors"
@@ -381,7 +362,6 @@ export function WorkersDashboard() {
             Refresh
           </button>
         </div>
-        </div>
 
         {error && (
           <div className="bg-red-50 border border-red-200 rounded-lg p-4">