A process-lifetime Capstan.SnapshotStore reference implementation.
Backed by an Agent holding one pipeline's %Capstan.Snapshot.State{} (nil until first
written). Durable only for the life of the process — a restart loses the snapshot progress
— so it is intended for tests and ephemeral pipelines, never a production durable
store. Rule 1 (Ch5): it holds the state in memory and never logs it.
Summary
Functions
Start a fresh store (the snapshot state begins nil).
Functions
@spec start_link(keyword()) :: Agent.on_start()
Start a fresh store (the snapshot state begins nil).