Add qmux crate and deprecate web-transport-ws (#191)

* Add qmux crate and deprecate web-transport-ws

Implement the QMux protocol (draft-ietf-quic-qmux-00) as a new crate
supporting multiplexing over TCP, TLS (feature-gated), and WebSocket
(feature-gated). The wire format is backwards-compatible with the legacy
webtransport encoding used by web-transport-ws.

The web-transport-ws Rust side is now a thin stub re-exporting from qmux.
The TypeScript polyfill is updated to support both webtransport and
qmux-00 wire formats via version-aware encode/decode.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Restructure qmux into feature-gated transport modules

Replace the monolithic Client/Server with feature-gated modules:
- qmux::tcp (feature = "tcp", default) — connect/accept functions
- qmux::tls (feature = "tls") — connect/accept with rustls
- qmux::ws  (feature = "ws")  — Client/Server builders + connect/accept for pre-upgraded WebSockets
- qmux::wss (feature = "wss") — WebSocket over TLS (rustls)

TCP is now also feature-gated for potential no-std use. Core
session/frame/stream types are always available.

Also addresses review feedback: fix hardcoded SNI "localhost", consume
DATAGRAM/QX_TRANSPORT_PARAMETERS payloads in decode, replace todo!()
panics with DatagramsUnsupported error, use expect instead of
unwrap_or for post-handshake invariant, accept bare qmux-00
unconditionally, make frame types pub(crate), return errors instead of
panicking on malformed VarInt/unsupported version.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add public proto module with wire format types and Transport trait

Move frame encoding/decoding and version types into a public `proto`
module. Rename FrameTransport to Transport and make Session::new() public
so users can implement custom transports.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix review findings: negotiation, error handling, and shim correctness

- Guard bare ALPN fallbacks in Server::accept with supported.is_empty()
- Return error from parse_negotiated_protocol on unrecognized headers
- Preserve tungstenite error details via Error::Io instead of Error::Closed
- Fix RecvStream::closed() to poll both channels when buffer is non-empty
- Error on lengthless DATAGRAM (0x30) over byte streams
- Remove duplicate constants in ws.rs, use crate-level imports
- Fix web-transport-ws shim: disable default features, forward wss feature
- Fix README migration snippet with correct qmux::ws imports

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Add cancellation safety warning to SessionState::run

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Improve public API: ALPNS const, Session::connect/accept, docstrings

- Replace individual ALPN_*/PREFIX_* public consts with ALPNS and
  PREFIXES slices so callers auto-support new versions
- Add Session::connect/accept, make Session::new private
- Enable all features by default (tls + wss)
- Add docstrings to all public types, traits, and methods
- Bump web-transport-ws to 0.4.0 (breaking: shim removed API surface)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix clippy single_match warning in session loop

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Fix wss feature conflict, error handling, and docs

- Add qmux wss-webpki-roots feature to avoid pulling in both root stores
- Fix web-transport-ws to use wss-webpki-roots for its webpki feature
- Preserve error details in ws::Client::connect instead of mapping to Closed
- Add comment explaining QX_TRANSPORT_PARAMETERS magic constant
- Simplify README migration diff to show only changed imports

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Remove wss-webpki-roots feature, drop webpki feature from shim

The deprecated web-transport-ws shim is the only consumer; new users
should use qmux directly and configure TLS roots themselves.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Split wss into wss-native-roots and wss-webpki-roots

Default to tls + ws without any root certificates, so server-only
usage doesn't pull in unnecessary root stores. Clients opt into
whichever root store they need.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Simplify TLS features: single wss with rustls native roots

No need for native-tls or webpki-roots variants — qmux already
uses rustls for TCP/TLS, so one wss feature with native roots
keeps it simple. Back in the default features.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Move TypeScript code from web-transport-ws to qmux, publish as @moq/qmux

- Move all TS source (session, frame, stream, varint) to qmux/
- Add package.json, tsconfig.json, build/release scripts to qmux/
- Stub web-transport-ws to re-export from @moq/qmux (deprecated)
- Remove deprecated Rust examples from web-transport-ws
- Add pnpm-workspace.yaml for workspace resolution

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Re-export tungstenite and tokio_tungstenite from qmux, bump to 0.0.2

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* More qmux changes.

* Send QX_TRANSPORT_PARAMETERS on qmux-00 WebSocket connections

The qmux spec requires this as the first frame. Without it, servers
reject the connection immediately.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Rename WebTransportWs

* PR improvements.

* fmt

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: kixelated

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+    "qmux",
     "web-transport",
     "web-transport-noq",
     "web-transport-proto",

bun.lock

@@ -3,6 +3,7 @@
 	"private": true,
 	"type": "module",
 	"workspaces": [
+		"qmux",
 		"web-demo",
 		"web-transport-ws"
 	],