修复jackson序列化bug

common/src/main/java/com/kym/common/config/JacksonConfig.java

@@ -148,7 +148,10 @@ public class JacksonConfig {
                         writer.assignSerializer(this.longSerializer);
                     }
                 } else if (isLocalDateTimeType(writer)) {
-                    writer.assignSerializer(this.localDateTimeSerializer);
+                    // 只在字段没有自定义序列化器时才设置，避免覆盖 jackson-datatype-jsr310 已注册的序列化器
+                    if (!writer.hasSerializer()) {
+                        writer.assignSerializer(this.localDateTimeSerializer);
+                    }
                 } else {
                     writer.assignNullSerializer(this.nullJsonSerializer);
                 }