fix: add spacing below dismiss alert on Runtime page

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/AgentHealth/AgentHealth.tsx

@@ -297,7 +297,7 @@ export default function AgentHealth() {
       {/* No agents warning + dismiss — shown when app-scoped, no agents, admin */}
       {appId && agentList.length === 0 && isAdmin && (
         <>
-          <Alert variant="warning" title="No agents connected">
+          <Alert variant="warning" title="No agents connected" className={styles.dismissAlert}>
             <span>
               {catalogEntry?.managed ? 'Managed app' : 'Discovered app'} &mdash; {(catalogEntry?.exchangeCount ?? 0).toLocaleString()} exchanges recorded.
               {' '}You can dismiss this application to remove it and all associated data.