Add quic-zig implementation (QUIC + WebTransport)

[endel]

Summary

Adds quic-zig — a pure Zig QUIC implementation (RFC 9000/9001/9002) with HTTP/3 and WebTransport support. Zero C dependencies. Docker image auto-built via GitHub Actions CI and published to ghcr.io/endel/quic-zig:latest.

The same Docker image serves both QUIC and WebTransport tests — the entrypoint script auto-detects WT mode and dispatches to dedicated WT server/client binaries.

Supported QUIC test cases (self-interop)

Test	Result
handshake	✅
transfer	✅
retry	✅
http3	✅
ecn	✅
multiplexing	✅
resumption	✅
zerortt	✅
keyupdate	✅
longrtt	✅
chacha20	✅
ipv6	✅
v2	✅
transferloss	✅
transfercorruption	✅
amplificationlimit	✅
rebind-port	✅
rebind-addr	✅
blackhole	❌
handshakeloss	❌
handshakecorruption	❌
connectionmigration	❌

18/22 QUIC test cases pass in self-interop.

Supported WebTransport test cases (self-interop)

Test	Abbr	Result
handshake	H	✅
transfer-unidirectional-receive	UR	✅
transfer-unidirectional-send	US	✅
transfer-bidirectional-receive	BR	✅
transfer-bidirectional-send	BS	✅
transfer-datagram-receive	DR	✅
transfer-datagram-send	DS	✅

7/7 WebTransport test cases pass in self-interop.

Endpoint details

• Dockerfile: interop/runner/Dockerfile — multi-stage build, extends martenseemann/quic-network-simulator-endpoint:latest
• Entry point: interop/runner/run_endpoint.sh — sources /setup.sh, dispatches on $ROLE, auto-detects WT mode via $PROTOCOLS
• Image: ghcr.io/endel/quic-zig:latest (linux/amd64)
• Role: both (client + server)
• QLOG: writes to $QLOGDIR when set
• SSLKEYLOGFILE: writes to $SSLKEYLOGFILE when set

Note

Add quic-zig implementation entry for QUIC and WebTransport interop tests

Registers quic-zig (image ghcr.io/endel/quic-zig:latest, role both) in implementations_quic.json and implementations_webtransport.json so it participates in both QUIC and WebTransport interop test matrices.

^{Macroscope summarized be7d83d.}

[marten-seemann]

Is this a private repository?

[endel]

Hi @marten-seemann, I hope you are well! It was still private... I just opened it! 🙌

[endel]

I've updated the PR to include the WebTransport implementation as well! 🙌