feat: Phase1安全基线 — 风险等级+审核超时+执行进度+通知脱敏+高危确认+维护窗口 (1119测试)

新增功能:
- ticket_sql_items模型: 逐条SQL执行记录(状态/耗时/影响行数)
- risk_evaluator.py: 4级风险评估(low/medium/high/critical), 支持MySQL/PG/Redis/Mongo
- Ticket模型: 新增risk_level + workflow_id字段
- 审核引擎签名改造: audit(sql, db_type, instance_id=None) 支持EXPLAIN预检
- 审核超时保护: 10s超时跳过审核, 防止工单创建阻塞
- 工单创建自动风险计算 + 审批流匹配(instance.workflow_id优先)
- SQL items查询API: GET /{ticket_id}/sql-items 含进度统计
- 执行器集成: 执行完成后自动更新SQL items逐条状态
- 通知脱敏: password/secret/token自动掩码, SQL预览截断100字符
- 高危操作强制二次确认: high/critical级别需confirmed=true
- 维护窗口控制: system_settings配置执行时间窗口(支持跨午夜)
- 45个新测试: 风险评估24+通知脱敏5+维护窗口2+SQL分类11+配置2

backend/app/schemas/ticket.py

@@ -9,6 +9,7 @@ class TicketCreate(BaseModel):
     instance_id: int
     target_database: str = Field(..., min_length=1)
     sql_content: str = Field(..., min_length=1)
+    sql_type: Optional[str] = None
     rollback_sql: Optional[str] = None
     reason: str = Field(..., min_length=5)
     priority: Literal["high", "medium", "low"] = "medium"
@@ -32,6 +33,8 @@ class TicketResponse(BaseModel):
     rollback_sql: Optional[str] = None
     status: str
     priority: str
+    risk_level: Optional[str] = "low"
+    workflow_id: Optional[int] = None
     applicant_id: int
     applicant_name: Optional[str] = None
     approver_id: Optional[int] = None