Nagle + the peer's delayed-ACK timer turns sub-MSS WS frames at 20ms
cadence into bursts with up-to-40ms stalls (axum #2521) — on the
plaintext :8080 listener behind ANY proxy. axum 0.7.9 (locked) carries
Serve::tcp_nodelay; the new rutster::serve::serve_with_nodelay wrapper
is the single production serve path so the sim-bench latency assertion
(Task 3) regresses exactly what main.rs runs.
Seam gate untouched: this is the HTTP/WS listener, not the RTP path.
Signed-off-by: Aaron D. Lee <himself@adlee.work>