feat(message): SSE 告警/体征推送添加医患关系过滤

alert.triggered 和 device.readings.synced 事件现在只推送给
该患者的管床医生（通过 patient_doctor_relation 表查询），
而非广播给租户内所有用户。新增 3 个单元测试验证 payload
解析逻辑。

crates/erp-message/src/handler/sse_handler.rs

@@ -3,6 +3,8 @@ use std::convert::Infallible;
 use axum::extract::Extension;
 use axum::response::sse::{Event, KeepAlive, Sse};
 use futures::stream::Stream;
+use sea_orm::ConnectionTrait;
+use uuid::Uuid;
 
 use erp_core::error::AppError;
 use erp_core::types::TenantContext;
@@ -24,6 +26,7 @@ pub async fn message_stream(
     // 空前缀 = 订阅所有事件
     let (mut rx, _handle) = state.event_bus.subscribe_filtered(String::new());
 
+    let db = state.db.clone();
     let sse_stream = async_stream::stream! {
         loop {
             match rx.recv().await {
@@ -48,6 +51,20 @@ pub async fn message_stream(
                                 .data(data));
                         }
                         "alert.triggered" => {
+                            // 医患关系过滤：只推送给该患者的管床医生
+                            let patient_id = event.payload.get("patient_id")
+                                .and_then(|v| v.as_str());
+                            if let Some(pid_str) = patient_id {
+                                let pid = Uuid::parse_str(pid_str).ok();
+                                if let Some(pid) = pid {
+                                    let is_doctor = is_doctor_for_patient(
+                                        &db, tenant_id, user_id, pid,
+                                    ).await;
+                                    if !is_doctor {
+                                        continue;
+                                    }
+                                }
+                            }
                             let data = serde_json::to_string(&event.payload)
                                 .unwrap_or_default();
                             yield Ok(Event::default()
@@ -55,6 +72,20 @@ pub async fn message_stream(
                                 .data(data));
                         }
                         "device.readings.synced" => {
+                            // 医患关系过滤：只推送给该患者的管床医生
+                            let patient_id = event.payload.get("patient_id")
+                                .and_then(|v| v.as_str());
+                            if let Some(pid_str) = patient_id {
+                                let pid = Uuid::parse_str(pid_str).ok();
+                                if let Some(pid) = pid {
+                                    let is_doctor = is_doctor_for_patient(
+                                        &db, tenant_id, user_id, pid,
+                                    ).await;
+                                    if !is_doctor {
+                                        continue;
+                                    }
+                                }
+                            }
                             let data = serde_json::to_string(&event.payload)
                                 .unwrap_or_default();
                             yield Ok(Event::default()
@@ -73,3 +104,89 @@ pub async fn message_stream(
 
     Ok(Sse::new(sse_stream).keep_alive(KeepAlive::default()))
 }
+
+/// 检查 user_id 对应的医生是否是某患者的管床医生。
+///
+/// 查询 `patient_doctor_relation` 表：
+/// - `doctor_id` 匹配 `user_id`（doctor_profile 主键即 user_id）
+/// - `patient_id` 匹配目标患者
+/// - 未软删除
+///
+/// 查询失败时返回 false（宁可漏推不可误推）。
+async fn is_doctor_for_patient(
+    db: &sea_orm::DatabaseConnection,
+    tenant_id: Uuid,
+    user_id: Uuid,
+    patient_id: Uuid,
+) -> bool {
+    let sql = sea_orm::Statement::from_sql_and_values(
+        sea_orm::DatabaseBackend::Postgres,
+        r#"SELECT COUNT(*) AS cnt FROM patient_doctor_relation
+           WHERE tenant_id = $1 AND doctor_id = $2 AND patient_id = $3 AND deleted_at IS NULL"#,
+        [
+            tenant_id.into(),
+            user_id.into(),
+            patient_id.into(),
+        ],
+    );
+    match db.query_one(sql).await {
+        Ok(Some(row)) => {
+            let cnt: i64 = row.try_get::<i64>("", "cnt").unwrap_or(0);
+            cnt > 0
+        }
+        _ => {
+            tracing::warn!(
+                user_id = %user_id,
+                patient_id = %patient_id,
+                "查询医患关系失败，跳过推送"
+            );
+            false
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// 验证 is_doctor_for_patient 函数签名和基础逻辑。
+    ///
+    /// 由于需要真实数据库连接，此处仅测试参数构造正确性。
+    /// 完整的数据库集成测试在 erp-health 的集成测试中覆盖。
+    #[test]
+    fn patient_id_parsing_from_payload() {
+        let payload = serde_json::json!({
+            "patient_id": "550e8400-e29b-41d4-a716-446655440000",
+            "severity": "critical",
+            "rule_name": "心率过高",
+        });
+        let pid_str = payload.get("patient_id").and_then(|v| v.as_str());
+        assert!(pid_str.is_some());
+        let pid = Uuid::parse_str(pid_str.unwrap()).ok();
+        assert!(pid.is_some());
+        assert_eq!(
+            pid.unwrap(),
+            Uuid::parse_str("550e8400-e29b-41d4-a716-446655440000").unwrap()
+        );
+    }
+
+    #[test]
+    fn patient_id_missing_returns_none() {
+        let payload = serde_json::json!({
+            "severity": "warning",
+        });
+        let pid_str = payload.get("patient_id").and_then(|v| v.as_str());
+        assert!(pid_str.is_none());
+    }
+
+    #[test]
+    fn patient_id_invalid_uuid_returns_none() {
+        let payload = serde_json::json!({
+            "patient_id": "not-a-uuid",
+        });
+        let pid_str = payload.get("patient_id").and_then(|v| v.as_str());
+        assert!(pid_str.is_some());
+        let pid = Uuid::parse_str(pid_str.unwrap()).ok();
+        assert!(pid.is_none());
+    }
+}