Capabilities
onUploadProgress and onDownloadProgress do nothing here — a unary RPC is one
message in and one message out. The client warns rather than silently never
calling your handler, because a progress bar frozen at zero reads as a hung app.
Streaming (server, client, bidi) is deliberately out of scope: it cannot return
Promise<T>, so it would change the shape of every generated method. Use
@tahanabavi/typesocket for streams.