fix: 修复SQLAlchemy 2.0+兼容性问题

- 使用sqlalchemy.orm.DeclarativeBase替代已弃用的ext.declarative
- 更新Record类继承新的BaseModel基类
- 更新metadata.create_all调用

src/models/database.py

@@ -7,11 +7,12 @@
 from datetime import datetime
 from typing import Optional
 from sqlalchemy import Column, Integer, String, Text, DateTime, JSON
-from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import create_engine
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import sessionmaker, DeclarativeBase
 
-Base = declarative_base()
+# 使用新版SQLAlchemy的DeclarativeBase
+class BaseModel(DeclarativeBase):
+    pass
 
 
 class RecordCategory:
@@ -34,7 +35,7 @@ class RecordCategory:
         return category in cls.all()
 
 
-class Record(Base):
+class Record(BaseModel):
     """记录模型 - 存储图片识别和AI处理结果"""
 
     __tablename__ = 'records'
@@ -139,7 +140,7 @@ class DatabaseManager:
         )
 
         # 创建所有表
-        Base.metadata.create_all(bind=self.engine)
+        BaseModel.metadata.create_all(bind=self.engine)
 
     def get_session(self):
         """