RadioTransport

Interface that transports (BLE, TCP, serial, etc.) must implement.

Transports are responsible for physical framing, buffering, and connection lifecycle. The SDK codec handles higher-level protocol framing (sync bytes, length, CRC).

Single collector rule: frames returns a cold flow that the SDK collects exactly once. Transports must not support multiple concurrent collectors (by design; the SDK owns the reader).

Thread safety: the SDK's engine actor calls connect, disconnect, send, and collects frames/state from a single coroutine context at a time. Transport implementations therefore do not need internal locking against the engine, but they must tolerate disconnect() being invoked at any point — including while a connect(), send(), or frame collection is in flight on another coroutine — and clean up promptly.