feat: 实现成长路径功能

- 新增数据库表: growth_path_nodes, user_growth_path_progress, user_node_completions
- 新增 Model: GrowthPathNode, UserGrowthPathProgress, UserNodeCompletion
- 新增 Service: GrowthPathService（管理端CRUD、学员端进度追踪）
- 新增 API: 学员端获取成长路径、管理端CRUD
- 前端学员端从API动态加载成长路径数据
- 更新管理端API接口定义

frontend/src/api/trainee/index.ts

@@ -40,7 +40,48 @@ export interface CourseMaterial {
   createdAt: string
 }
 
-// 成长路径节点
+// 成长路径节点（学员端）
+export interface TraineeGrowthPathNode {
+  id: number
+  course_id: number
+  title: string
+  description?: string
+  stage_name?: string
+  is_required: boolean
+  estimated_days: number
+  order_num: number
+  status: 'locked' | 'unlocked' | 'in_progress' | 'completed'
+  progress: number
+  course_name?: string
+  course_cover?: string
+}
+
+// 成长路径阶段
+export interface TraineeGrowthPathStage {
+  name: string
+  description?: string
+  completed: number
+  total: number
+  nodes: TraineeGrowthPathNode[]
+}
+
+// 成长路径（学员端响应）
+export interface TraineeGrowthPath {
+  id: number
+  name: string
+  description?: string
+  position_id?: number
+  position_name?: string
+  total_progress: number
+  completed_nodes: number
+  total_nodes: number
+  status: 'not_started' | 'in_progress' | 'completed'
+  started_at?: string
+  estimated_completion_days?: number
+  stages: TraineeGrowthPathStage[]
+}
+
+// 兼容旧接口
 export interface GrowthPathNode {
   id: number
   courseId: number
@@ -54,7 +95,7 @@ export interface GrowthPathNode {
   order: number
 }
 
-// 成长路径
+// 兼容旧接口
 export interface GrowthPath {
   id: number
   name: string
@@ -226,10 +267,35 @@ export const markMaterialCompleted = (materialId: number) => {
 }
 
 /**
- * 获取成长路径
+ * 获取成长路径（学员端）
  */
-export const getGrowthPath = () => {
-  return request.get<GrowthPath>('/api/v1/trainee/growth-path')
+export const getGrowthPath = (positionId?: number) => {
+  return request.get<TraineeGrowthPath>('/api/v1/trainee/growth-path', {
+    params: positionId ? { position_id: positionId } : {}
+  })
+}
+
+/**
+ * 开始学习成长路径
+ */
+export const startGrowthPath = (growthPathId: number) => {
+  return request.post<{ success: boolean; message: string; progress_id: number }>('/api/v1/trainee/growth-path/start', {
+    growth_path_id: growthPathId
+  })
+}
+
+/**
+ * 完成成长路径节点
+ */
+export const completeGrowthPathNode = (nodeId: number) => {
+  return request.post<{
+    completed: boolean
+    total_progress: number
+    is_path_completed: boolean
+    unlocked_nodes: number[]
+  }>('/api/v1/trainee/growth-path/node/complete', {
+    node_id: nodeId
+  })
 }
 
 /**