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-health/src/handler/device_reading_handler.rs

@@ -7,7 +7,7 @@ use uuid::Uuid;
 
 use erp_core::error::AppError;
 use erp_core::rbac::require_permission;
-use erp_core::types::{ApiResponse, PaginatedResponse, TenantContext};
+use erp_core::types::{ApiResponse, TenantContext};
 
 use crate::service::device_reading_service;
 use crate::state::HealthState;