v1.4.0: generic Stream[T] — typed stream messages, drop (T, *Stream, error)

- Stream[T]: Send(v T) type-safe; message type recovered from the
  instantiated Send signature (reflect has no type-args API)
- method signatures reduced to (error), (T, error), (*Stream[T], error);
  the (T, *Stream, error) first-message form is gone — send it via Send
- return T and stream message T now run checkType at bind time
  (Stream[any] remains the explicit untyped escape hatch)
- generated clients: TS onMessage: (data: T); Go <-chan T
- fix vacuous panic assertions (fmt.Sprint(nil) -> "<nil>") in
  hardening/route test catch helpers

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

stream_protocol_test.go

@@ -14,17 +14,17 @@ import (
 
 type ProtocolStreamSvc struct{}
 
-func (*ProtocolStreamSvc) Empty() (*Stream, error) {
-	stream := &Stream{}
+func (*ProtocolStreamSvc) Empty() (*Stream[any], error) {
+	stream := &Stream[any]{}
 	go stream.Close()
 	return stream, nil
 }
 
-func (*ProtocolStreamSvc) Before() (*Stream, error) {
+func (*ProtocolStreamSvc) Before() (*Stream[any], error) {
 	return nil, errors.New("before stream")
 }
 
-func (*ProtocolStreamSvc) Business() (*Stream, error) {
+func (*ProtocolStreamSvc) Business() (*Stream[any], error) {
 	return nil, Error(4201, "business before stream")
 }