traceId missing from MDC in logs in Dubbo 3.3.2

In Dubbo latest version 3.3.2, MDC.get("traceId") returns null even though the log pattern includes %X{traceId}. The call chain is web -> dubbo -> platform -> domains. Question: Is manual MDC.put required in a preHandler to propagate traceId?

Start by reproducing the issue on Dubbo 3.3.2 with a log pattern containing %X{traceId}, checking MDC.get("traceId") across the web → dubbo → platform → domains call chain. Determine whether traceId is propagated automatically or requires manual MDC.put in a preHandler; done means the expected traceId is available in MDC and logs, or the required configuration is documented.

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