fix(hypercore): log WebSocket close frames instead of warning "binary msg"

[xxivq]

Stream::poll_next decodes only OpCode::Text and routes every other frame into
log::warn!("Hyperliquid sent a binary msg? {data:?}").

Hyperliquid rotates long-lived websocket connections, closing them with a normal
1000 close frame and the reason "Expired". So a perfectly healthy connection
emits a spurious warning on every rotation — about 9 times a day on a collector I
run, which is otherwise clean:

WARN hypersdk::hypercore::ws: Hyperliquid sent a binary msg? b"\x03\xe8Expired"
INFO hypersdk::hypercore::ws: Disconnected from wss://api.hyperliquid.xyz/ws, attempting to reconnect...

\x03\xe8 is 1000. It isn't a binary message; it's a close frame, and the SDK
already depends on yawc, which exposes close::CloseCode.

What this changes

Matches on the opcode instead of testing for Text:

• Close decodes the RFC 6455 §5.5.1 status code and reason, logging at INFO.
• Ping / Pong / Continuation are traced. (yawc's assemble_incoming
  reassembles fragments and yields them under their original opcode, so a raw
  Continuation never reaches here — that arm is defensive only.)
• Binary keeps the original warning, which now means what it says.
• Text is untouched, including its unable to parse warning.

What this does not change

Control flow is identical. Every arm falls through to the next loop iteration
exactly as the previous else did; only the Text arm returns
Poll::Ready(Some(_)). The stream still ends when the peer closes, so the
reconnect loop in run_ws still fires. Only log levels and message text differ.

Tests

Adds a #[cfg(test)] mod tests for decode_close, including the exact payload
Hyperliquid sends on rotation (b"\x03\xe8Expired" → CloseCode::Normal,
"Expired"), a close frame with no reason, and payloads too short to carry a
status code.

cargo test --lib passes (139 tests). cargo clippy adds no new warnings —
examples/hypercore/priority-fee-bid.rs already fails to build on main,
unrelated to this change. cargo fmt clean.

🤖 Generated with Claude Code

[kiarash666]

• https://github.com/infinitefield/hypersdk