feat(db): device_readings 新增 metric 字段用于多行拆分存储

crates/erp-health/src/entity/device_readings.rs

@@ -11,6 +11,8 @@ pub struct Model {
     #[sea_orm(skip_serializing_if = "Option::is_none")]
     pub device_id: Option<String>,
     pub device_type: String,
+    #[sea_orm(nullable)]
+    pub metric: Option<String>,
     #[sea_orm(skip_serializing_if = "Option::is_none")]
     pub device_model: Option<String>,
     pub raw_value: serde_json::Value,

crates/erp-health/src/service/device_reading_service.rs

@@ -207,6 +207,7 @@ async fn batch_insert_readings(
             patient_id: Set(patient_id),
             device_id: Set(Some(device_id.to_string())),
             device_type: Set(r.device_type.clone()),
+            metric: Set(r.values.get("metric").and_then(|v| v.as_str()).map(String::from)),
             device_model: Set(device_model.map(String::from)),
             raw_value: Set(r.values.clone()),
             measured_at: Set(*measured_at),