The Stage-0 usability fix: tapir serve runs discovery for all users on an
interval (reusing the existing Runner.Loop, enumerate-users-then-withUser),
auto-summarize defaults ON for Future-B users so the list fills itself, and the
ADR-014 process-wide per-egress-IP rate gate is confirmed/finished in the same
slice because in-process + auto + multi-user makes it load-bearing. Records the
single-replica constraint as load-bearing, and a fallback (auto-summarize OFF
until the gate exists) so the dangerous combination never ships half-built.
