Read-side processor replays unhandled events on every restart

Read-side processor replays unhandled events on every restart: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). I'm using Lagom's read-side support (this happens in both Cassandra and JDBC backends, so I think the issue is shared across them, but I noticed it first…

The task

I'm using Lagom's read-side support (this happens in both Cassandra and JDBC backends, so I think the issue is shared across them, but I noticed it first with `CassandraReadSide`).

Part of FineEnvs/MiMo-V2.6-RL-harbor-code.