feat: 新增告警、成本、配额、微信模块及缓存服务

- 新增告警模块 (alerts): 告警规则配置与触发
- 新增成本管理模块 (cost): 成本统计与分析
- 新增配额模块 (quota): 配额管理与限制
- 新增微信模块 (wechat): 微信相关功能接口
- 新增缓存服务 (cache): Redis 缓存封装
- 新增请求日志中间件 (request_logger)
- 新增异常处理和链路追踪中间件
- 更新 dashboard 前端展示
- 更新 SDK stats_client 功能

backend/app/models/alert.py

@@ -0,0 +1,108 @@
+"""告警相关模型"""
+from datetime import datetime
+from sqlalchemy import Column, Integer, BigInteger, String, Text, Enum, SmallInteger, JSON, TIMESTAMP
+from ..database import Base
+
+
+class AlertRule(Base):
+    """告警规则表"""
+    __tablename__ = "platform_alert_rules"
+    
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    name = Column(String(100), nullable=False)  # 规则名称
+    description = Column(Text)  # 规则描述
+    
+    # 规则类型
+    rule_type = Column(Enum(
+        'error_rate',      # 错误率告警
+        'call_count',      # 调用次数告警
+        'token_usage',     # Token使用量告警
+        'cost_threshold',  # 费用阈值告警
+        'latency',         # 延迟告警
+        'custom'           # 自定义告警
+    ), nullable=False)
+    
+    # 作用范围
+    scope_type = Column(Enum('global', 'tenant', 'app'), default='global')  # 作用范围类型
+    scope_value = Column(String(100))  # 作用范围值，如租户ID或应用代码
+    
+    # 告警条件
+    condition = Column(JSON, nullable=False)  # 告警条件配置
+    # 示例: {"metric": "error_count", "operator": ">", "threshold": 10, "window": "5m"}
+    
+    # 通知配置
+    notification_channels = Column(JSON)  # 通知渠道列表
+    # 示例: [{"type": "wechat_bot", "webhook": "https://..."}, {"type": "email", "to": ["a@b.com"]}]
+    
+    # 告警限制
+    cooldown_minutes = Column(Integer, default=30)  # 冷却时间(分钟)，避免重复告警
+    max_alerts_per_day = Column(Integer, default=10)  # 每天最大告警次数
+    
+    # 状态
+    status = Column(SmallInteger, default=1)  # 0-禁用 1-启用
+    priority = Column(Enum('low', 'medium', 'high', 'critical'), default='medium')  # 优先级
+    
+    created_at = Column(TIMESTAMP, default=datetime.now)
+    updated_at = Column(TIMESTAMP, default=datetime.now, onupdate=datetime.now)
+
+
+class AlertRecord(Base):
+    """告警记录表"""
+    __tablename__ = "platform_alert_records"
+    
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    rule_id = Column(Integer, nullable=False, index=True)  # 关联的规则ID
+    rule_name = Column(String(100))  # 规则名称（冗余，便于查询）
+    
+    # 告警信息
+    alert_type = Column(String(50), nullable=False)  # 告警类型
+    severity = Column(Enum('info', 'warning', 'error', 'critical'), default='warning')  # 严重程度
+    title = Column(String(200), nullable=False)  # 告警标题
+    message = Column(Text)  # 告警详情
+    
+    # 上下文
+    tenant_id = Column(String(50), index=True)  # 相关租户
+    app_code = Column(String(50))  # 相关应用
+    metric_value = Column(String(100))  # 触发告警的指标值
+    threshold_value = Column(String(100))  # 阈值
+    
+    # 通知状态
+    notification_status = Column(Enum('pending', 'sent', 'failed', 'skipped'), default='pending')
+    notification_result = Column(JSON)  # 通知结果
+    notified_at = Column(TIMESTAMP)  # 通知时间
+    
+    # 处理状态
+    status = Column(Enum('active', 'acknowledged', 'resolved', 'ignored'), default='active')
+    acknowledged_by = Column(String(100))  # 确认人
+    acknowledged_at = Column(TIMESTAMP)  # 确认时间
+    resolved_at = Column(TIMESTAMP)  # 解决时间
+    
+    created_at = Column(TIMESTAMP, default=datetime.now, index=True)
+
+
+class NotificationChannel(Base):
+    """通知渠道配置表"""
+    __tablename__ = "platform_notification_channels"
+    
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    name = Column(String(100), nullable=False)  # 渠道名称
+    
+    channel_type = Column(Enum(
+        'wechat_bot',   # 企微机器人
+        'email',        # 邮件
+        'sms',          # 短信
+        'webhook',      # Webhook
+        'dingtalk'      # 钉钉
+    ), nullable=False)
+    
+    # 渠道配置
+    config = Column(JSON, nullable=False)
+    # wechat_bot: {"webhook": "https://qyapi.weixin.qq.com/cgi-bin/webhook/send?key=xxx"}
+    # email: {"smtp_host": "...", "smtp_port": 465, "username": "...", "password_encrypted": "..."}
+    # webhook: {"url": "https://...", "method": "POST", "headers": {...}}
+    
+    # 状态
+    status = Column(SmallInteger, default=1)  # 0-禁用 1-启用
+    
+    created_at = Column(TIMESTAMP, default=datetime.now)
+    updated_at = Column(TIMESTAMP, default=datetime.now, onupdate=datetime.now)