feat(mux/rust): make cargo-publish ready for v0.1.0

- Add version to donglora-client dependency for crates.io
- Set TCP_NODELAY on accepted TCP connections for low-latency framing
- Add CHANGELOG.md

CHANGELOG.md

@@ -0,0 +1,20 @@
+# Changelog
+
+## 0.1.0 — 2026-04-06
+
+Initial release.
+
+### Features
+
+- USB multiplexer daemon: share one DongLoRa dongle with multiple applications
+- Unix domain socket and optional TCP listeners (same COBS-framed protocol)
+- RxPacket broadcast to all connected clients
+- Reference-counted StartRx/StopRx across clients
+- Config locking: first client sets radio config, others must match or fail
+- Auto-reconnect on USB hot-plug with ping verification
+- Bounded per-client send queues (256 frames) with backpressure isolation
+- Smart interception: redundant commands get synthetic responses without
+  hitting the dongle
+- Graceful shutdown on SIGINT/SIGTERM with socket cleanup
+- TCP_NODELAY on accepted connections for low-latency frame delivery
+- CLI: `--port`, `--socket`, `--tcp`, `--verbose` options