添加后台管理功能

功能:
- 数据概览仪表盘
- 用户管理(列表/编辑/删除)
- 翻译记录管理
- 缓存管理
- 统计报表(图表)
- 操作日志

管理员账号: admin / admin123
后台地址: /admin/

models.py

@@ -19,7 +19,7 @@ class User(db.Model):
     email = db.Column(db.String(120), unique=True, nullable=False)
     password_hash = db.Column(db.String(256), nullable=False)
     
-    # 用户类型: guest, free, vip_basic, vip_pro, vip_enterprise
+    # 用户类型: guest, free, vip_basic, vip_pro, vip_enterprise, admin
     user_type = db.Column(db.String(20), default='free')
     
     # 会员信息
@@ -34,6 +34,10 @@ class User(db.Model):
     created_at = db.Column(db.DateTime, default=datetime.utcnow)
     updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
     
+    # 状态
+    is_active = db.Column(db.Boolean, default=True)     # 是否启用
+    is_admin = db.Column(db.Boolean, default=False)     # 是否管理员
+    
     # 关系
     translations = db.relationship('Translation', backref='user', lazy=True)
     
@@ -92,8 +96,12 @@ class User(db.Model):
             'email': self.email,
             'user_type': self.user_type,
             'is_vip': self.is_vip(),
+            'is_admin': self.is_admin,
+            'is_active': self.is_active,
             'daily_count': self.daily_count,
             'total_count': self.total_count,
+            'created_at': self.created_at.isoformat() if self.created_at else None,
+            'membership_expire': self.membership_expire.isoformat() if self.membership_expire else None,
         }
 
 
@@ -145,8 +153,10 @@ class Translation(db.Model):
             'status': self.status,
             'progress': self.progress,
             'from_cache': self.from_cache,
+            'file_size': self.file_size,
             'created_at': self.created_at.isoformat() if self.created_at else None,
             'completed_at': self.completed_at.isoformat() if self.completed_at else None,
+            'user_id': self.user_id,
         }
 
 
@@ -163,6 +173,7 @@ class TranslationCache(db.Model):
     # 缓存信息
     cache_path = db.Column(db.String(255), nullable=False)  # 缓存文件路径
     page_count = db.Column(db.Integer, nullable=False)
+    file_size = db.Column(db.Integer, default=0)
     
     # 统计
     hit_count = db.Column(db.Integer, default=0)  # 缓存命中次数
@@ -194,6 +205,67 @@ class GuestTranslation(db.Model):
     
     # 统计
     daily_count = db.Column(db.Integer, default=0)
+    total_count = db.Column(db.Integer, default=0)
     last_translate_date = db.Column(db.Date, nullable=True)
     
-    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+
+# ==================== 系统配置模型 ====================
+class SystemConfig(db.Model):
+    """系统配置表"""
+    __tablename__ = 'system_config'
+    
+    id = db.Column(db.Integer, primary_key=True)
+    key = db.Column(db.String(100), unique=True, nullable=False)
+    value = db.Column(db.Text, nullable=True)
+    description = db.Column(db.String(255), nullable=True)
+    updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+    
+    @staticmethod
+    def get(key, default=None):
+        config = SystemConfig.query.filter_by(key=key).first()
+        return config.value if config else default
+    
+    @staticmethod
+    def set(key, value, description=None):
+        config = SystemConfig.query.filter_by(key=key).first()
+        if config:
+            config.value = value
+        else:
+            config = SystemConfig(key=key, value=value, description=description)
+            db.session.add(config)
+        db.session.commit()
+
+
+# ==================== 操作日志模型 ====================
+class OperationLog(db.Model):
+    """操作日志表"""
+    __tablename__ = 'operation_logs'
+    
+    id = db.Column(db.Integer, primary_key=True)
+    
+    # 操作者
+    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=True)
+    username = db.Column(db.String(80), nullable=True)
+    
+    # 操作信息
+    action = db.Column(db.String(50), nullable=False)  # login, translate, register, etc.
+    target = db.Column(db.String(100), nullable=True)  # 操作对象
+    detail = db.Column(db.Text, nullable=True)         # 详细信息(JSON)
+    
+    # IP地址
+    ip_address = db.Column(db.String(45), nullable=True)
+    
+    # 时间
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    
+    def to_dict(self):
+        return {
+            'id': self.id,
+            'username': self.username,
+            'action': self.action,
+            'target': self.target,
+            'ip_address': self.ip_address,
+            'created_at': self.created_at.isoformat() if self.created_at else None,
+        }