Order state machine (ARCHITECTURE.md §9.5). Explicit client-side states with
a guarded transition table — no optimistic guesswork. Pure and fully testable.
pending_place ─ack→ working ─fill→ filled
─reject→ rejected
working/partial ─submitModify→ modify_pending ─ack→ working / ─reject→ working
working/partial ─submitCancel→ cancel_pending ─cancelled→ cancelled / ─reject→ working
any non-terminal ─reconnectAbsent→ stale
Order state machine (ARCHITECTURE.md §9.5). Explicit client-side states with a guarded transition table — no optimistic guesswork. Pure and fully testable.
pending_place ─ack→ working ─fill→ filled ─reject→ rejected working/partial ─submitModify→ modify_pending ─ack→ working / ─reject→ working working/partial ─submitCancel→ cancel_pending ─cancelled→ cancelled / ─reject→ working any non-terminal ─reconnectAbsent→ stale