智教助手平台：完整初始化

- 前端：Vue3 + TS + Element Plus，24 个页面路由（课件/组题/教案/动画/思维导图/作文批改/命题/课堂/资源/社区等）
- 后端：FastAPI + SQLAlchemy + SQLite，17 个路由模块，AI 服务层含降级模板
- AI：glm-5.x 推理模型已禁用思维链，确保输出真实内容
- 修复：ai_service 两处请求体注入 enable_thinking/thinking disabled
- 测试账号：13900999999 / test1234

backend/models/classroom.py

@@ -0,0 +1,20 @@
+from sqlalchemy import Column, DateTime, ForeignKey, Integer, JSON, String, Text, func
+from sqlalchemy.orm import relationship
+from database import Base
+
+
+class ClassroomActivity(Base):
+    __tablename__ = "classroom_activities"
+
+    id = Column(Integer, primary_key=True, index=True)
+    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    title = Column(String(200), nullable=False)
+    activity_type = Column(String(50), default="poll")
+    description = Column(Text, default="")
+    config = Column(JSON, default=dict)
+    responses = Column(JSON, default=list)
+    status = Column(String(20), default="draft")
+    created_at = Column(DateTime, server_default=func.now())
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now())
+
+    author = relationship("User")