Mentat

Events with duplicate IDs cannot be saved into db. It's deliberate, as ID is also used as primary key. However, duplicate IDs should be inspected and originators notified - either their IDs do not have sufficient entropy, or their connectors generate duplicate messages for whatever reason.

Bonus: originator can be notified automatically if duplicate ID comes from the same connector.

We should either watch logs or propagate error into runlog and report from there.