feat: 新增二级菜单子导航系统（SubNav + redirectMenu）

- 新增 SubNav 组件：Navbar 下方水平子导航条，展示当前二级菜单下的三级页面，支持滚动和下拉分组
- 新增 redirectMenu 页面：点击二级菜单时卡片式展示子页面列表
- SidebarItem 深度 >=1 时改为叶子节点渲染（小圆点标记），激活高亮回退到二级菜单
- Navbar 布局重构为 Flexbox，面包屑/SubNav 根据场景切换
- 新增 productionLine Vuex 模块，轧辊研磨页改为 store 方式读取产线数据
- Sidebar activeMenu 逻辑增强：自动定位当前页所属二级菜单

klp-ui/src/views/mes/roll/grind/index.vue

@@ -494,9 +494,9 @@
 <script>
 import { listRollInfo, getRollInfo, addRollInfo, updateRollInfo, delRollInfo } from '@/api/mes/roll/rollInfo'
 import { listRollGrind, addRollGrind, updateRollGrind, delRollGrind, getMonthlyStats } from '@/api/mes/roll/rollGrind'
-import { listProductionLine } from '@/api/wms/productionLine'
 import { listData, addData, updateData, delData } from '@/api/system/dict/data'
 import rollLineMixin from '../rollLineMixin'
+import { mapGetters } from 'vuex'
 
 export default {
   name: 'GrindRoom',
@@ -504,7 +504,6 @@ export default {
   dicts: ['mes_roll_operator'],
   data() {
     return {
-      productionLines: [],
       filterLineId: null,
       lineTabOrder: [],
 
@@ -549,6 +548,8 @@ export default {
   },
 
   computed: {
+    ...mapGetters(['productionLines']),
+
     currentUserName() {
       return this.$store.state.user.name || this.$store.getters.name || ''
     },
@@ -606,9 +607,7 @@ export default {
       this.filterLineId = this.lineId
       const uid = this.$store.state.user?.userId || 0
       try { this.lineTabOrder = JSON.parse(localStorage.getItem(`grind_line_order_${uid}`) || '[]') } catch { /* ignore */ }
-      listProductionLine({ pageNum: 1, pageSize: 100 }).then(res => {
-        this.productionLines = res.rows || []
-      })
+      this.$store.dispatch('productionLine/getProductionLines')
       this.loadRolls()
     },