Thin wrapper around Elixir Registry for locating per-session runtimes.
SessionServer processes can be named via via_tuple/2, enabling lookup
by session_id without hardcoding process names.
Summary
Types
Functions
@spec child_spec(keyword()) :: Supervisor.child_spec()
@spec lookup(registry(), session_id()) :: {:ok, pid()} | :error
@spec via_tuple(registry(), session_id()) :: {:via, Registry, {registry(), session_id()}}