A driver-adjacent Ruby control-plane over ruby-pg/libpq. It multiplexes independent, session-neutral extended-protocol operations from many fibers onto a small number of PostgreSQL connections while keeping explicit transactions and session-changing work on exclusive pinned connections. Requires any Fiber::Scheduler host (Async::Scheduler, Itsi::Scheduler, …); the gem does not depend on a particular reactor. Control-plane only: all wire work stays in libpq.