Expand description
Budget reset scanner.
Scans ff:idx:{b:M}:budget_resets per budget partition, finding budgets
whose next_reset_at score is <= now. For each, calls
FCALL ff_reset_budget which zeroes usage counters, records the reset
event, computes the next reset time, and re-scores in the index.
Reference: RFC-008 §Budget Reset, RFC-010 §6.11