feat: 全量功能模块开发与集成测试修复

- 新增后端模块：Alert、APIAsset、Compliance、Lineage、Masking、Risk、SchemaChange、Unstructured、Watermark
- 新增前端模块页面与API接口
- 新增Alembic迁移脚本(002-014)覆盖全量业务表
- 新增测试数据生成脚本与集成测试脚本
- 修复metadata模型JSON类型导入缺失导致启动失败的问题
- 修复前端Alert/APIAsset页面request模块路径错误
- 更新docker-compose与开发计划文档

backend/app/models/alert.py

@@ -0,0 +1,46 @@
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Text, DateTime, Boolean, ForeignKey, JSON
+from sqlalchemy.orm import relationship
+from app.core.database import Base
+
+
+class AlertRule(Base):
+    __tablename__ = "alert_rule"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(200), nullable=False)
+    trigger_condition = Column(String(50), nullable=False)  # l5_count, risk_score, schema_change
+    threshold = Column(Integer, default=0)
+    severity = Column(String(20), default="medium")
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+
+
+class AlertRecord(Base):
+    __tablename__ = "alert_record"
+
+    id = Column(Integer, primary_key=True, index=True)
+    rule_id = Column(Integer, ForeignKey("alert_rule.id"), nullable=False)
+    title = Column(String(200), nullable=False)
+    content = Column(Text)
+    severity = Column(String(20), default="medium")
+    status = Column(String(20), default="open")  # open, acknowledged, resolved
+    created_at = Column(DateTime, default=datetime.utcnow)
+
+    rule = relationship("AlertRule")
+
+
+class WorkOrder(Base):
+    __tablename__ = "work_order"
+
+    id = Column(Integer, primary_key=True, index=True)
+    alert_id = Column(Integer, ForeignKey("alert_record.id"), nullable=True)
+    title = Column(String(200), nullable=False)
+    description = Column(Text)
+    assignee_id = Column(Integer, ForeignKey("sys_user.id"), nullable=True)
+    status = Column(String(20), default="open")  # open, in_progress, resolved
+    resolution = Column(Text)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    resolved_at = Column(DateTime, nullable=True)
+
+    assignee = relationship("User")