Implements 6 io_uring network vtable entries (listen, accept, connect, read, write, send) that are stubbed as Unavailable upstream (zig#31723). The patch is applied at build time inside the Docker container only — it modifies the zig stdlib bundled in the container image, not the host zig installation or any downstream consumer of zat/websocket.zig. DNS (netLookup) is deliberately NOT patched — subscribers resolve hostnames through pool_io (Threaded) and pass the connected stream to the websocket client for TLS + framing via Evented io. Dep bumps: - websocket.zig 80c6434: initWithStream() respects config.tls (was hardcoded to null). Non-breaking — existing callers default to tls=false and get identical behavior. - zat v0.3.0-alpha.16: picks up the websocket bump so both zlay and zat resolve to the same websocket version. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>