refactor: 重构消息类型的初始化逻辑，新增各消息类型的构造函数以提高代码可读性和可维护性

message/forward.go

@@ -32,18 +32,26 @@ type NodeMessageData struct {
 
 func init() {
 	RegisterMessageType(TypeForward, func() CQMessage {
-		return &ForwardMessage{Type: TypeForward}
+		return NewForwardMessage()
 	})
 	RegisterMessageType(TypeNode, func() CQMessage {
-		return &NodeMessage{Type: TypeNode}
+		return NewNodeMessage()
 	})
 }
 
+func NewForwardMessage() *ForwardMessage {
+	return &ForwardMessage{Type: TypeForward}
+}
+
 // ForwardMessage methods
 func (msg *ForwardMessage) SetData(data json.RawMessage) error {
 	return json.Unmarshal(data, &msg.Data)
 }
 
+func NewNodeMessage() *NodeMessage {
+	return &NodeMessage{Type: TypeNode}
+}
+
 func (msg *ForwardMessage) ToCQString() string {
 	return fmt.Sprintf("[CQ:forward,id=%s]", msg.Data.ID)
 }