Expand description
Delayed execution promoter scanner.
Iterates ff:idx:{p:N}:lane:<lane_id>:delayed for each partition,
finding executions whose delay_until score is <= now. For each,
calls FCALL ff_promote_delayed to move them from delayed to eligible.
Note: ff_promote_delayed is Phase 2 Lua. For Phase 1, this scanner discovers due executions and logs them. The actual promotion requires knowing the lane_id (embedded in the delayed ZSET key), which in turn requires knowing which lanes exist. Phase 1 uses a single “default” lane.
Reference: RFC-010 §6, function #27