feat(syslog): 优化大日志通道并增加异常连续消费兜底

- 128 KiB 及以上日志默认进入大日志 Topic
- InfluxDB 原文及达梦大字段超过 256 KiB 时截断保存
- 截断内容追加 HB_XDR_TRUNCATED 标记
- InfluxDB 写入失败时继续执行规则解析和达梦写入
- 未知或系统性异常优先写入普通/大日志 DLT
- DLT 写入失败时记录特殊告警并提交 offset，避免阻塞后续消息
- DLT 失败等待时间默认限制为 1 秒
- 增加连续性放行、DLT 成功及失败监控指标
- 更新 Docker Compose、v3 升级文档及相关测试

haobang-security-dm/syslog-consumer-rule/src/main/java/com/common/service/DmLargeTextLimiter.java

@@ -18,13 +18,13 @@ import java.util.concurrent.atomic.LongAdder;
 public class DmLargeTextLimiter {
     private static final long MIN_ENABLED_LIMIT = 64L;
 
-    @Value("${dm.normal.large-field-max-utf8-bytes:0}")
+    @Value("${dm.normal.large-field-max-utf8-bytes:262144}")
     private long normalMaxBytes;
 
     @Value("${dm.normal.large-fields:http_req_body,http_resp_body,http_req_header,http_resp_header,detail,description,cmdline,shell_cmdline,parent_cmdline,mail_message}")
     private String normalFieldsValue;
 
-    @Value("${dm.non-normal.large-field-max-utf8-bytes:0}")
+    @Value("${dm.non-normal.large-field-max-utf8-bytes:262144}")
     private long nonNormalMaxBytes;
 
     private volatile Set<String> normalFields = Collections.emptySet();