Pure bounded endpoint state for QUIC external IO.
The first UDP adapter binds a concrete local address. Wildcard and
ancillary destination/interface metadata are intentionally unsupported.
enqueue/4 is admission only; local_send/4 reports the later local
writer result. Peer ACKs belong to Quic.Recovery, never this IO budget.
Summary
Types
@type send_ref() :: reference()
@type t() :: %Quic.IO.Endpoint{ address_validated: term(), bytes_pending: term(), bytes_received: term(), bytes_sent: term(), closed: term(), generation: term(), handshake_deadline: term(), idle_deadline: term(), in_flight: term(), max_queue: term(), max_queue_bytes: term(), queue: term(), queue_bytes: term(), timers: term() }