Track mux usage with a static AtomicBool. Once a mux connection
succeeds, all future connect() calls in the same process only try
the mux. connect() blocks waiting for the socket to reappear;
try_connect() returns an error so callers can retry with backoff.
When a mux socket file exists, connect(None, timeout) and try_connect()
now commit to the mux — returning an error if unreachable instead of
silently falling through to USB serial. This prevents a race condition
where a client could steal the serial port from the mux during reconnect.
Callers with explicit port = Some(...) are unaffected.
- Add ping-on-connect handshake: all connect functions validate the device
within 200ms, rejecting non-DongLoRa serial devices immediately
- Add try_connect() — non-blocking connect that errors instead of blocking
forever when no USB device is present
- Add payload size validation in transmit() (max 256 bytes)
- Add ErrorCode: impl std::error::Error
- Fix drain_rx error handling (no longer swallows original error)
- Fix repository URL to github.com/donglora/client-rs
- Remove wire-level tag constants from top-level re-exports
- Add rust-version (MSRV 1.85), homepage, exclude fields to Cargo.toml
- Add examples/ping.rs
- Allow clippy unwrap/expect in test modules
- Track serial timeout in field instead of returning hardcoded 2s
- Always restore timeout in drain_rx, even on read errors
- Handle EINTR/Interrupted in read_frame (retry instead of error)
- Use connect_timeout for TCP mux (no more 2-min hangs)
- Set write timeout on mux sockets (unix + tcp)
- Log unexpected unsolicited frames in recv via tracing::warn
- Add unix socket timeout test for WouldBlock handling
- Add CHANGELOG.md, remove resolved CLAUDE_TODO.md
swaits