bug: HTTP/3 live roundtrip test fails with response timeout when MOONLIGHT_HTTP3_TEST=1

[rudraditya21]

The explicit live HTTP/3 roundtrip test is failing in network/proto even though normal HTTP/3 unit tests pass when the env flag is not set.

Repro

MOONLIGHT_HTTP3_TEST=1 cargo test -p proto http3::tests::http3_roundtrip -- --nocapture

Expected

http3::tests::http3_roundtrip should pass (client gets 200 with body ok).

Actual

Test fails with:

• http3 roundtrip failed: Some(Parse("http3 response timeout"))

Notes

• Non-live HTTP/3 tests pass when MOONLIGHT_HTTP3_TEST is not set.
• This appears specific to the live client/server roundtrip path.
• Area to investigate: HTTP/3 server event/response path in network/proto/src/http3/mod.rs (stream completion/response emission/flush timing).