Between the registry miss and the eager session.title write, another
writer can take the canonical title (peer dm minting server-side, a
second machine, cross-connection sync). UNIQUE(title) rejects our write
with 'already in use' — which the compat path previously read as 'old
gateway' and prompted into OUR stray lazy session, forking the forever
chat. A uniqueness rejection now re-consults the registry and adopts the
winner; the zero-message stray is abandoned to the gateway pruner.
Genuine old-gateway failures (unknown method) keep the compat kickoff.
Teknium
d22e2b9f6e