Wait for input during Live.Hook.emit.
Default: one blocking GLib.MainContext.iteration. That is enough when emit runs off the request-dispatch stack.
**Socket servers that call sync Live.Hook.emit from inside a dispatched GI method** must override: the connection io watch cannot run again while on_input_ready is still on the stack, so iteration never reads the client's RPC-Live-Callback.reply. Override with GLib.poll on the socket fd, then Bin.Stream.parse and OLLMrpc.Request.dispatch (same body as on_input_ready inner loop). on_input_ready itself does not need to change.