fix: 修复dashboard路由父子节点都显示导致的菜单重复"数据概览"

子路由/dashboard/index缺少showLink: false，导致其在菜单中与父路由各显示一条

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

haha-admin-web/src/router/modules/dashboard.ts

@@ -14,7 +14,8 @@ export default {
       component: () => import("@/views/dashboard/index.vue"),
       meta: {
         icon: "ri:bar-chart-box-line",
-        title: "数据概览"
+        title: "数据概览",
+        showLink: false
       }
     }
   ]