When a peer's registration wins a name a local session was logged into,
that session authenticated against a credential that no longer exists.
The node now clears its accountname (the ircd emits RPL_LOGGEDOUT) and
tells the user why. A new outbound channel lets the engine push these
services-initiated actions to the uplink from the gossip path, drained
by the link loop alongside incoming traffic.
Nodes run anti-entropy over a TCP link: each advertises its version
vector, the peer replies with the log entries it lacks, and ingest is
idempotent so re-delivery and reconnect after a split both converge.
The engine is shared behind a mutex; config gains [gossip] and [[peer]].
Protocol-agnostic core: a Protocol trait maps raw server-to-server lines to a
normalized event/action model, so the engine never touches a raw line and a new
ircd is one new module. Adds event-log state (state is a fold over the log) and
a service framework. First protocol impl links to an InspIRCd (insp4) uplink —
completes the CAPAB/SERVER handshake, bursts, and introduces NickServ.
