feat(health): 事件驱动集成 + 数据一致性修复 + 逾期随访检查

- event.rs 重写为有状态处理器（订阅 workflow.task.completed / message.sent）
- module.rs on_startup 初始化 HealthCrypto 并注册事件处理器
- consultation_service 消息发送改为事务包裹（INSERT + CAS 原子更新）
- appointment_service 取消预约释放排班名额增加下限保护
- appointment_service update_schedule 增加 max_appointments >= current_appointments 校验
- follow_up_service 新增 complete_task_by_system 和 check_overdue_tasks
- validation.rs 随访状态机增加 overdue 状态支持
- main.rs 启动时运行逾期随访检查后台任务

crates/erp-health/src/module.rs

@@ -17,6 +17,21 @@ impl HealthModule {
         Self
     }
 
+    /// 启动定时逾期随访检查（每 6 小时运行一次）
+    pub fn start_overdue_checker(db: sea_orm::DatabaseConnection) {
+        tokio::spawn(async move {
+            let mut interval = tokio::time::interval(std::time::Duration::from_secs(6 * 3600));
+            loop {
+                interval.tick().await;
+                match crate::service::follow_up_service::check_overdue_tasks(&db).await {
+                    Ok(count) if count > 0 => tracing::info!(count = count, "随访逾期检查完成"),
+                    Ok(_) => {}
+                    Err(e) => tracing::warn!(error = %e, "随访逾期检查失败"),
+                }
+            }
+        });
+    }
+
     pub fn public_routes<S>() -> Router<S>
     where
         crate::state::HealthState: axum::extract::FromRef<S>,
@@ -235,8 +250,29 @@ impl ErpModule for HealthModule {
         vec!["auth"]
     }
 
-    fn register_event_handlers(&self, bus: &EventBus) {
-        crate::event::register_handlers(bus);
+    fn register_event_handlers(&self, _bus: &EventBus) {
+        // 事件处理器已迁移到 on_startup，此处保留空实现以兼容 trait 签名
+    }
+
+    async fn on_startup(&self, ctx: &erp_core::module::ModuleContext) -> erp_core::error::AppResult<()> {
+        let crypto = crate::crypto::HealthCrypto::from_keys(
+            &std::env::var("HEALTH_AES_KEY").unwrap_or_default(),
+            &std::env::var("HEALTH_HMAC_KEY").unwrap_or_default(),
+        )
+        .unwrap_or_else(|_| {
+            tracing::warn!("HEALTH_AES_KEY / HEALTH_HMAC_KEY 未设置或无效，使用开发默认密钥");
+            crate::crypto::HealthCrypto::dev_default()
+        });
+
+        let state = crate::state::HealthState {
+            db: ctx.db.clone(),
+            event_bus: ctx.event_bus.clone(),
+            crypto,
+        };
+
+        crate::event::register_handlers_with_state(state);
+        tracing::info!(module = "health", "Health module event handlers registered via on_startup");
+        Ok(())
     }
 
     async fn on_tenant_created(