feat: add job monitoring link to admin dashboard

Add Job Monitoring card to admin dashboard with:
- Hero icon for visual identification
- Brief description of monitoring capabilities
- Link to /admin/monitoring dashboard

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

lib/towerops_web/live/admin/dashboard_live.html.heex

@@ -57,6 +57,21 @@
           Open Dashboard →
         </.link>
       </div>
+
+      <div class="bg-white dark:bg-gray-800/50 rounded-lg border border-gray-200 dark:border-white/10 p-6">
+        <h2 class="text-lg font-semibold text-gray-900 dark:text-white mb-2">
+          <.icon name="hero-cpu-chip" class="w-5 h-5 inline mr-1" /> Job Monitoring
+        </h2>
+        <p class="text-sm text-gray-600 dark:text-gray-400 mb-4">
+          Real-time polling and discovery job monitoring
+        </p>
+        <.link
+          navigate={~p"/admin/monitoring"}
+          class="text-blue-600 dark:text-blue-400 hover:underline text-sm"
+        >
+          Open Monitoring →
+        </.link>
+      </div>
     </div>
 
     <div class="bg-white dark:bg-gray-800/50 rounded-lg border border-gray-200 dark:border-white/10">