The presence-sync tick iterates accounts serially with await on each
agent-login + PUT round-trip — a single tick can easily run 20+s when
there are several accounts. setInterval(intervalMs) does NOT wait for
the previous tick to finish, so on a busy gateway the next tick fires
on top of a still-running one and two parallel iterations each PUT
the same agentId within ~10 ms. That tipped the guild backend's
first-time-insert race (separate fix in nav/Fabric.Backend.Guild) into
500s on prod (caught in t2 gateway 2026-05-25 23:23:35Z; 6 of 6 agents
showed paired log lines 4-10 ms apart for the same agent → idle).
Fix: a simple `inflight` boolean. tick() returns immediately if
already running; the next interval beat catches up. lastStatus !==
bridge.get gating already means status changes catch the next tick
anyway, so skipping a beat costs nothing the next beat won't fix.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
hzhang
9419d270e5