Unified async Rust API for 47 exchange connectors (REST + WebSocket). The core layer — pure ExchangeHub + connectors. Higher-level builder, persistence, replay, OB tracker live in `digdigdig3-station`.
//! # L3 — Full Stack Connectors (L1 + L2 + Execution)
//!//! Split into two access tiers:
//! - **open/** — Works without registration or API keys (CEX, DEX, prediction markets)
//! - **gated/** — Requires account, API keys, or KYC (brokers)
pubmodopen;pubmodgated;