Engine (ws_client.c/h):
- Replace cJSON with jsmn (stack tokens, zero malloc) for book updates
- Quick-route message frames ("type":"message") to jsmn, bypass cJSON
- Coalesce same-symbol updates within one SSL_read burst: evaluate once
- ws_client_process_frame returns symbol_idx for batch tracking
- Restore book->sequence field update from sequence/sequenceNum
Executor (ws_client.py):
- Fix race: fill event arriving before await_fill registers future
is now detected via FillAccumulator._done flag, resolved immediately
Two-process architecture: a C17 fused engine (WebSocket order book
mirror, triangle enumeration, real-time profitability evaluation)
communicating via Unix domain socket to a Python 3 executor (order
placement with paper/live trading modes, REST control API).
Targets KuCoin spot market.