bump websocket.zig to 3c6794a (fix handshake POST body hang)
Handshake.parse used endsWith("\r\n\r\n") to detect a complete request,
which is only true for header-only GETs. Any POST with a body never
matched, so parse returned null forever and the handshake worker hung
until the connection's idle timeout.
Symptom in zlay: the reconnect cronjob POSTs requestCrawl through the
same socket as the firehose. Every request stalled, no PDSes were
re-announced, and the job hit its activeDeadlineSeconds.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>