Set Up Event Store Persistence Layer

[duhowise]

Implement persistent storage for aggregate events using Akka.Persistence or a compatible event store with Akkatecture support.

Tasks:

• Evaluate available storage adapters (SQL, EventStoreDb, etc.).
• Configure persistence for VotingAggregate (and others in future).
• Document event store setup and Akka.ActorSystem integration.
• Reference configuration example:

// akka.conf
// ... see code example in docs