fix: 编辑策略页面资产配置自动填充问题

- 使用 splice/push 替代直接赋值，保持 Vue 响应式引用
- 修复 tags 字段类型不一致（数组 -> 字符串）
- 使用 String() 安全转换 targetWeight 数字类型
- 添加 Array.isArray 检查增强健壮性

pages/strategies/edit/edit.vue

@@ -273,7 +273,7 @@ const formData = ref({
   name: '',
   description: '',
   riskLevel: 'medium',
-  tags: [],
+  tags: '',
   maType: 'SMA',
   shortPeriod: '',
   longPeriod: '',
@@ -529,12 +529,16 @@ const loadStrategyDetail = async (id) => {
           formData.value.lookbackPeriod = params.lookbackPeriod?.toString() || '';
           formData.value.rebalanceThreshold = params.rebalanceThreshold?.toString() || '';
           console.log('📊 再平衡策略 assets:', params.assets);
-          if (params.assets && params.assets.length > 0) {
-            formData.value.assets = params.assets.map(asset => ({
+          if (params.assets && Array.isArray(params.assets) && params.assets.length > 0) {
+            // 使用 splice 保持响应式引用
+            formData.value.assets.splice(0, formData.value.assets.length);
+            params.assets.forEach(asset => {
+              formData.value.assets.push({
                 symbol: asset.symbol || '',
-              targetWeight: asset.targetWeight?.toString() || ''
-            }));
-            console.log('📊 填充后的 formData.assets:', formData.value.assets);
+                targetWeight: asset.targetWeight != null ? String(asset.targetWeight) : ''
+              });
+            });
+            console.log('📊 填充后的 formData.assets:', JSON.stringify(formData.value.assets));
           }
           break;
         case 'chandelier_exit':