The inline-egress fast path (which lifted the WS/SSE broadcast ceiling on the common path) skips connections using registered/fixed files (worker.go guard). On kernels that use fixed files the fan-out still funnels through the worker thread, so the io_uring broadcast win is conditional. Extend the fast path to those conns.
The inline-egress fast path (which lifted the WS/SSE broadcast ceiling on the common path) skips connections using registered/fixed files (worker.go guard). On kernels that use fixed files the fan-out still funnels through the worker thread, so the io_uring broadcast win is conditional. Extend the fast path to those conns.