fix: 修复学员端成长路径数据解析，兼容直接返回数据格式

frontend/src/views/trainee/growth-path.vue

@@ -490,8 +490,12 @@ const loadGrowthPath = async () => {
   growthPathLoading.value = true
   try {
     const response = await getGrowthPath()
+    // 兼容两种响应格式：直接返回数据 或 { code, data } 格式
     if (response.code === 200 && response.data) {
       growthPathData.value = response.data
+    } else if (response.id && response.stages) {
+      // API 直接返回数据对象
+      growthPathData.value = response
     }
   } catch (error) {
     console.error('加载成长路径失败:', error)