REQUOTE is now distinct from QUOTE:
QUOTE: PLACE new order (no existing to cancel)
REQUOTE: CANCEL_REPLACE existing + place new (immediate)
CHASE: PLACE with short TTL (auto-cancel retry)
CANCEL: Remove existing order
action_menu generates REQUOTE with metadata={'requote': True} for existing orders.
DSL REQUOTE produces CANCEL_REPLACE when existing order, falls back to PLACE.
All 800+ tests pass.