fix(core): 跨 crate 小修复 — dto 合并、tracing 补全、死代码清理

- erp-ai: 删除孤立 dto.rs（已合并到子模块）
- erp-core: audit_service tracing 优化
- erp-health: points_handler 补充返回值、alert_engine 修正日志级别
- erp-plugin: host/data_handler/market_handler tracing 统一
- erp-dialysis/event: 移除无用 import
- erp-workflow/executor: tracing 格式统一

crates/erp-core/src/audit_service.rs

@@ -1,7 +1,7 @@
 use crate::audit::AuditLog;
 use crate::entity::audit_log;
 use crate::request_info::RequestInfo;
-use sea_orm::{ActiveModelTrait, ColumnTrait, ConnectionTrait, EntityTrait, QueryFilter, QueryOrder, Set};
+use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter, QueryOrder, Set};
 use sha2::{Sha256, Digest};
 use tracing;