fix(clients/rust): harden client resilience for v0.1.0 release

- 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

src/lib.rs

@@ -31,7 +31,7 @@ pub mod transport;
 // Flat re-exports for convenience
 pub use client::Client;
 pub use codec::{decode_frame, encode_frame, read_frame, FrameReader};
-pub use connect::{connect, connect_default, default_socket_path};
+pub use connect::{connect, connect_default, connect_mux_auto, default_socket_path};
 pub use discovery::{find_port, wait_for_device, USB_PID, USB_VID};
 pub use protocol::{
     Bandwidth, Command, ErrorCode, RadioConfig, Response, CMD_TAG_SET_CONFIG, CMD_TAG_START_RX,