添加登录功能：JWT认证、注册、登录、前端登录页面

backend/models.py

@@ -1,5 +1,23 @@
 from sqlalchemy import Column, Integer, String, Float, DateTime, Text, func
 from database import Base
+import hashlib
+
+
+class User(Base):
+    """用户表"""
+    __tablename__ = "user"
+
+    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
+    username = Column(String(50), unique=True, nullable=False, index=True, comment="用户名")
+    password_hash = Column(String(128), nullable=False, comment="密码哈希")
+    nickname = Column(String(50), nullable=True, comment="昵称")
+    created_at = Column(DateTime, server_default=func.now(), comment="创建时间")
+
+    def set_password(self, password):
+        self.password_hash = hashlib.sha256(password.encode()).hexdigest()
+
+    def check_password(self, password):
+        return self.password_hash == hashlib.sha256(password.encode()).hexdigest()
 
 
 class Inventory(Base):