feat: 初始化考培练系统项目

- 从服务器拉取完整代码
- 按框架规范整理项目结构
- 配置 Drone CI 测试环境部署
- 包含后端(FastAPI)、前端(Vue3)、管理端

技术栈: Vue3 + TypeScript + FastAPI + MySQL

backend/app/models/position_course.py

@@ -0,0 +1,28 @@
+"""
+岗位课程关联模型
+"""
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, Boolean, Enum, UniqueConstraint
+from sqlalchemy.orm import relationship
+from app.models.base import BaseModel, SoftDeleteMixin
+
+
+class PositionCourse(BaseModel, SoftDeleteMixin):
+    """岗位课程关联表"""
+    __tablename__ = "position_courses"
+    
+    # 添加唯一约束：同一岗位下同一课程只能有一条有效记录
+    __table_args__ = (
+        UniqueConstraint('position_id', 'course_id', 'is_deleted', name='uix_position_course'),
+    )
+    
+    position_id = Column(Integer, ForeignKey("positions.id"), nullable=False, comment="岗位ID")
+    course_id = Column(Integer, ForeignKey("courses.id"), nullable=False, comment="课程ID")
+    
+    # 课程类型：required（必修）、optional（选修）
+    course_type = Column(String(20), default="required", nullable=False, comment="课程类型")
+    priority = Column(Integer, default=0, comment="优先级/排序")
+    
+    # 关系
+    position = relationship("Position", back_populates="courses")
+    course = relationship("Course", back_populates="position_assignments")