@spec belongs_to(
  strategy :: struct(),
  hub :: ProcessHub.Hub.t(),
  child_ids :: [ProcessHub.child_id()],
  replication_factor :: pos_integer()
) :: %{required(ProcessHub.child_id()) => [node()]}

Returns a map of child_id to list of nodes where the child process belongs to.

The map is used to determine where the child process should be started or migrated to.

@spec children_init(struct(), ProcessHub.Hub.t(), [map()], keyword()) ::
  :ok | {:error, any()}

Perform any necessary initialization and validation for the started children.

@spec deterministic?(struct()) :: boolean()

Returns whether this distribution strategy produces deterministic results based solely on the node topology.

Deterministic strategies (like ConsistentHashing) always produce the same distribution for the same set of nodes. Non-deterministic strategies (like CentralizedLoadBalancer) may produce different distributions based on runtime factors like node load.

This is used to optimize child validation - deterministic strategies can skip revalidation when topology signature matches.

@spec distribution_signature(
  struct(),
  ProcessHub.Hub.t()
) :: non_neg_integer()

Computes a distribution signature based on the current state that affects distribution.

For deterministic strategies (like ConsistentHashing), this is typically based on the sorted list of cluster nodes. For non-deterministic strategies (like CentralizedLoadBalancer), this may include additional state like load scores.

Used to detect if distribution-relevant state has changed between request creation and execution.

Returns an integer hash that uniquely identifies the current distribution state.

@spec init(
  struct(),
  ProcessHub.Hub.t()
) :: struct()

Triggered when coordinator is initialized.

Could be used to perform initialization.