fix(agents): navigate to detail page before invalidating list query

After creating an agent from the empty state, the query invalidation
triggered a refetch that re-rendered the agents list page (empty → list)
before navigation to the detail page completed, causing a visible flash.

Move navigation.push() before qc.invalidateQueries() so the user lands
on the detail page immediately; the list refetch happens in the
background after we've already left.

packages/views/agents/components/agents-page.tsx

@@ -279,10 +279,10 @@ export function AgentsPage() {
         // Surfaced softly; the agent itself is fine.
       }
     }
-    qc.invalidateQueries({ queryKey: workspaceKeys.agents(wsId) });
     setShowCreate(false);
     setDuplicateTemplate(null);
     navigation.push(paths.agentDetail(agent.id));
+    qc.invalidateQueries({ queryKey: workspaceKeys.agents(wsId) });
   };
 
   const handleDuplicate = useCallback((agent: Agent) => {