Measure timings

It would be interesting to learn how fast we get a reply from the wallet. This helps us to optimize the product and understand how fast things generally are.

I am not sure if this can be done with some datadog instrumentation or if the echo logs with timings are enough.
Alternatively we can add a manual timing entry to the log (starting a timer when we publish the message and log the time once we receive the reply)

Start by locating the wallet message publish and reply handling paths, then review the existing echo logs. Compare whether timing data should use Datadog instrumentation or a manual log entry. Done means consistently recording the elapsed time for wallet replies in a way that supports product performance analysis.

Written by the indexing model from the issue text.