gflog-slf4j bridge adds "null" suffix to the bridged output

AI analysis:

>There is a null suffix on every bridged message (e.g., ...Started ExchangeApp in 3.5 seconds (process running for 7.452)null). This is a cosmetic issue from the gflog-slf4j bridge appending a null throwable.
>
>The null suffix comes from a bug in gflog-slf4j's bridge: SLF4JBridgeHandler in SLF4J 2.x always calls info(message, throwable) even when throwable is null, and gflog's bridge unconditionally does entry.append(message).appendLast(throwable), printing "null" for a null throwable.

Start by locating the gflog-slf4j bridge and the entry point that handles SLF4J 2.x calls with a null throwable. Reproduce a bridged log message, then verify that a null throwable no longer appears as a "null" suffix while real throwable output remains intact.

Written by the indexing model from the issue text.