Implement comprehensive WebSocket subscription stability fixes

- Resolved critical issues causing subscriptions to drop after 30-60 seconds due to unconsumed receiver channels.
- Introduced per-subscription consumer goroutines to ensure continuous event delivery and prevent channel overflow.
- Enhanced REQ parsing to handle both wrapped and unwrapped filter arrays, eliminating EOF errors.
- Updated publisher logic to correctly send events to receiver channels, ensuring proper event delivery to subscribers.
- Added extensive documentation and testing tools to verify subscription stability and performance.
- Bumped version to v0.26.2 to reflect these significant improvements.

app/handle-message.go

@@ -142,8 +142,7 @@ func (l *Listener) HandleMessage(msg []byte, remote string) {
 		if !strings.Contains(err.Error(), "context canceled") {
 			log.E.F("%s message processing FAILED (type=%s): %v", remote, t, err)
 			// Don't log message preview as it may contain binary data
-
-			// Send error notice to client (use generic message to avoid control chars in errors)
+ 			// Send error notice to client (use generic message to avoid control chars in errors)
 			noticeMsg := fmt.Sprintf("%s processing failed", t)
 			if noticeErr := noticeenvelope.NewFrom(noticeMsg).Write(l); noticeErr != nil {
 				log.E.F(