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

clients/rust/CHANGELOG.md

@@ -0,0 +1,27 @@
+# Changelog
+
+## 0.1.0 — 2026-04-06
+
+Initial release.
+
+### Features
+
+- High-level `Client<T>` with send/recv and command helpers (ping, set_config,
+  start_rx, stop_rx, transmit, get_config, get_mac, display_on, display_off)
+- COBS wire framing via `ucobs` (matches firmware implementation)
+- Auto-detection connection: TCP mux, Unix socket mux, direct USB serial
+- Bounded RX packet buffering (256 packets, FIFO eviction)
+- `FrameReader` accumulator for streaming byte sources
+- USB device discovery by VID:PID with blocking wait
+
+### Resilience
+
+- Cross-platform timeout handling: `TimedOut` (Windows) and `WouldBlock`
+  (Linux/macOS) both treated as clean timeouts in `read_frame`
+- `EINTR`/`Interrupted` signals retried automatically in `read_frame`
+- `drain_rx` always restores the original timeout, even on I/O errors
+- TCP mux connections use `connect_timeout` (bounded by caller's timeout)
+- Mux sockets set both read and write timeouts
+- `SerialTransport` tracks timeout accurately for save/restore
+- Unexpected unsolicited frames logged via `tracing::warn` instead of silently
+  discarded