The Windows client now reports runtime errors in its graceful disconnect
message so relay logs can show why a client stopped. That message comes from
an anyhow error chain, so keep it useful but bounded before sending it over the
control stream and using it as the QUIC close reason.
Truncate client shutdown messages to 1024 bytes, preserving UTF-8 boundaries
and adding an ellipsis when truncation happens. Normal shutdown text and small
error chains are unchanged.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
Refs: MVP Windows client diagnostics hardening
ddidderr
5a65b62a3d