Adapter module implementing both the evoq_event_store surface and the evoq_snapshot_adapter behaviour.

Configured into evoq via:

  application:set_env(evoq, event_store_adapter, mem_evoq_adapter),
  application:set_env(evoq, snapshot_store_adapter, mem_evoq_adapter).

Every callback looks up the store pid in mem_evoq_registry and forwards via gen_server:call/2. The store itself (mem_evoq_store) holds the actual state.

Note that two seams cross this module: read paths translate #event{} to #evoq_event{} before returning; snapshot reads translate #snapshot{} to #evoq_snapshot{}. mac, signature and anchor_hash are intentionally NOT propagated — they are storage- layer concerns.