fix(client): reject a message over the daemon's size limit instead of reconnecting in a loop

The daemon closes the WebSocket with 1009 when a message exceeds its 100 MiB
limit. A workspace or agent creation that loses its connection mid-request
stays pending and, after reconnecting, finds no record of itself on the
daemon (the oversized frame was never read), so it resubmits the same frame
and the connection drops again every couple of seconds until the app reloads.

The client now checks each outbound frame against the same limit, which
protocol exports and the daemon sets explicitly, and fails that request with
a size error while the connection stays up.

Refs #5501

packages/protocol/src/websocket-message-limit.ts

@@ -0,0 +1,2 @@
+/** Largest WebSocket message the daemon accepts. A bigger one closes the connection with 1009. */
+export const MAX_WEBSOCKET_MESSAGE_BYTES = 100 * 1024 * 1024;