feat(tree): implement tree component with checkbox support and manager pattern

- Added core Tree component (BimTree, BimTreeNode)
- Added TreeManager for lifecycle management
- Added ModelTreeManager for business logic encapsulation (Tree + Dialog)
- Integrated into BimEngine and updated demos
- Added internationalization support

demo-vue/src/App.vue

@@ -20,6 +20,8 @@
           <button @click="openTestDialog">测试弹窗</button>
           <button @click="openInfoDialog">信息弹窗</button>
           <button @click="openRedDialog">警告弹窗</button>
+          <button @click="openTreeDialog">树组件测试</button>
+          <button @click="openSimpleTreeDialog">纯树测试</button>
         </div>
       </div>
 
@@ -181,6 +183,67 @@ const openRedDialog = () => {
   });
 };
 
+const openTreeDialog = () => {
+  if (!engine.value || !engine.value.modelTree) return;
+
+  // 1. 构造树数据
+  const treeData = [
+    {
+      id: 'root',
+      label: 'tree.modelStruct', // 翻译键
+      expanded: true,
+      children: [
+        {
+          id: 'level-1',
+          label: 'tree.floor1',
+          expanded: true,
+          children: [
+            { id: 'l1-wall', label: 'tree.wall', checked: true },
+            { id: 'l1-col', label: 'tree.column' },
+            { id: 'l1-win', label: 'tree.window' },
+            { id: 'l1-door', label: 'tree.door' }
+          ]
+        },
+        {
+          id: 'level-2',
+          label: 'tree.floor2',
+          children: [
+            { id: 'l2-wall', label: 'tree.wall' },
+            { id: 'l2-col', label: 'tree.column' }
+          ]
+        }
+      ]
+    }
+  ];
+
+  // 2. 使用高级 API
+  engine.value.modelTree.showStructTree(treeData);
+};
+
+const openSimpleTreeDialog = () => {
+  if (!engine.value || !engine.value.modelTree) return;
+
+  const treeData = [
+    {
+      id: 'menu-root',
+      label: 'menu.home',
+      expanded: true,
+      icon: '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path></svg>',
+      children: [
+        { id: 'm-info', label: 'menu.info' },
+        {
+          id: 'm-struct', label: 'tree.modelStruct', children: [
+            { id: 'm-w', label: 'tree.wall' },
+            { id: 'm-c', label: 'tree.column' }
+          ]
+        }
+      ]
+    }
+  ];
+
+  engine.value.modelTree.showSimpleTree(treeData, 'Simple Tree');
+};
+
 // --- 工具栏操作 ---
 const toggleToolbar = () => {
   if (!engine.value || !engine.value.toolbar) return;