the relay SIGSEGV'd at ~396 hosts during startup — DiskPersist's pg.Pool was created on Threaded Io, but ~40 call sites across slurper, API handlers, broadcaster, backfiller, and cleaner called it from Evented fibers, triggering Thread.current() on a NULL threadlocal. Part A — dual pg.Pool: add ev_db (Evented pg.Pool) to DiskPersist. pure DB methods get *Impl(db) internal implementations + thin *Ev wrappers. Evented callers use ev_db; pool_io callers keep using self.db. 13 methods refactored. Part B — Threaded service paths: - admin ban: uidForDidEv on Evented side, takedown routed through host_ops queue (fire-and-forget). worker executes takeDownUser + persist + broadcast on pool_io under persist_order. - playback: cross-Io request/reply via MPSC Treiber stack. Evented fiber posts PlaybackRequest, pool_io worker executes playback() under mutex, sets done atomic. fiber spin-waits on failure to prevent use-after-free on stack-local request. persist_order held through full persist → resequence → broadcast_queue.push() to guarantee insertion order matches seq assignment order. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>