submodule对gitea不管用，所以直接拉了一份拉格兰

Lagrange.Core/Lagrange.OneBot/Message/Entity/TextSegment.cs

@@ -0,0 +1,29 @@
+using System.Text.Json.Serialization;
+using Lagrange.Core.Message;
+using Lagrange.Core.Message.Entity;
+
+namespace Lagrange.OneBot.Message.Entity;
+
+[Serializable]
+public partial class TextSegment(string text)
+{
+    public TextSegment() : this("") { }
+
+    [JsonPropertyName("text")] [CQProperty] public string Text { get; set; } = text;
+}
+
+[SegmentSubscriber(typeof(TextEntity), "text")]
+public partial class TextSegment : SegmentBase
+{
+    public override void Build(MessageBuilder builder, SegmentBase segment)
+    {
+        if (segment is TextSegment textSegment) builder.Text(textSegment.Text);
+    }
+    
+    public override SegmentBase FromEntity(MessageChain chain, IMessageEntity entity)
+    {
+        if (entity is not TextEntity textEntity) throw new ArgumentException("Invalid entity type.");
+        
+        return new TextSegment(textEntity.Text);
+    }
+}