fix: preserve mileage metadata on location events

modules/inbound/inbound-mqtt/src/main/java/com/lingniu/ingest/inbound/mqtt/mapper/YutongEventMapper.java

@@ -16,6 +16,7 @@ import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Base64;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
 
@@ -96,10 +97,13 @@ public final class YutongEventMapper implements EventMapper<MqttPayload> {
                     speed == null ? 0.0 : speed,
                     direction == null ? 0.0 : direction,
                     0, 0);
+            Map<String, String> locationMeta = mileage == null
+                    ? meta
+                    : withMeta(meta, "total_mileage_km", formatDouble(mileage));
             out.add(new VehicleEvent.Location(
                     UUID.randomUUID().toString(),
                     vin, ProtocolId.MQTT_YUTONG, payload.deviceTime(), ingestTime,
-                    null, meta, loc));
+                    null, locationMeta, loc));
         }
         return out;
     }
@@ -233,6 +237,13 @@ public final class YutongEventMapper implements EventMapper<MqttPayload> {
         }
     }
 
+    private static String formatDouble(double value) {
+        String formatted = String.format(Locale.ROOT, "%.6f", value);
+        return formatted.indexOf('.') < 0
+                ? formatted
+                : formatted.replaceAll("0+$", "").replaceAll("\\.$", "");
+    }
+
     private record IdentityResolution(VehicleIdentity identity, String errorMessage) {
         private static IdentityResolution ok(VehicleIdentity identity) {
             return new IdentityResolution(identity, null);

modules/inbound/inbound-mqtt/src/test/java/com/lingniu/ingest/inbound/mqtt/YutongEventMapperTest.java

@@ -73,6 +73,7 @@ class YutongEventMapperTest {
         VehicleEvent.Location loc = (VehicleEvent.Location) events.stream()
                 .filter(e -> e instanceof VehicleEvent.Location).findFirst().orElseThrow();
         assertThat(loc.payload().longitude()).isEqualTo(116.397128, org.assertj.core.data.Offset.offset(0.000001));
+        assertThat(loc.metadata()).containsEntry("total_mileage_km", "123456.7");
     }
 
     @Test