fix: remove unused fields and ensure push notifications work in cloned clients

- Remove unused Timestamp and Source fields from PushNotificationInfo
- Add pushProcessor to newConn function to ensure Conn instances have push notifications
- Add push notification methods to Conn type for consistency
- Ensure cloned clients and Conn instances preserve push notification functionality

This fixes issues where:
1. PushNotificationInfo had unused fields causing confusion
2. Conn instances created via client.Conn() lacked push notification support
3. All client types now consistently support push notifications

push_notifications.go

@@ -225,10 +225,8 @@ const (
 
 // PushNotificationInfo contains metadata about a push notification.
 type PushNotificationInfo struct {
-	Command   string
-	Args      []interface{}
-	Timestamp int64
-	Source    string
+	Command string
+	Args    []interface{}
 }
 
 // ParsePushNotificationInfo extracts information from a push notification.