torque:reload --drain wrote {prefix}paused without a TTL; after the master
handover nothing deleted it, so every reload left all workers refusing
pickup until a manual torque:pause continue. The drain now sets the key
with drain_grace_seconds + 60 expiry (a drain's pause only needs to outlive
its own window); a deliberate torque:pause keeps its no-TTL semantics. The
master additionally warns at boot when starting into a paused queue.