A stream dropped once the relay has asked to close a WebTransport session
would send its FIN or STOP_SENDING at once, ahead of the WT_CLOSE_SESSION
capsule. In a browser on the build host, a page whose stream was stopped
just before the close lost its renderer (reproduced on loopback: a page
writing a stream the relay refused crashed in most runs). The binding now
keeps such streams (WtSend, WtRecv hold the connection's Closing) until the
QUIC connection has closed, at most ten seconds, when they end with nothing
more on the wire; read_setup keeps the stream it refuses in `early`, so it
too is dropped after the close.
tests/webtransport_close.rs: a stream that breaks a rule before SETUP is
refused with PROTOCOL_VIOLATION, and the client reads the close and no
STOP_SENDING ahead of it.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
d6abac7c4b