feat: Add CreateWeChatUser API

src/Plugins/BotSharp.Plugin.MongoStorage/Repository/MongoRepository.WeChatUser.cs

@@ -10,4 +10,31 @@ public partial class MongoRepository
         return weChatUser != null ? weChatUser.ToWeChatUser() : null;
     }
 
+    public WeChatUser? CreateWeChatUser(WeChatUser weChatUser)
+    {
+        if (weChatUser == null) return null;
+
+        var weChatUserInfo = new WeChatUserDocument
+        {
+            Id = weChatUser.Id ?? Guid.NewGuid().ToString(),
+            OpenId = weChatUser.OpenId,
+            SessionKey = weChatUser.SessionKey,
+            UnionId = weChatUser.UnionId,
+            Sex = weChatUser.Sex,
+            Province = weChatUser.Province,
+            City = weChatUser.City,
+            NickName = weChatUser.NickName,
+            Headimgurl = weChatUser.Headimgurl,
+            PhoneNumber = weChatUser.PhoneNumber,
+            Country = weChatUser.Country,
+            Privilege = weChatUser.Privilege,
+            CreatedAt = DateTime.UtcNow,
+        };
+
+        _dc.WeChatUsers.InsertOne(weChatUserInfo);
+
+        return weChatUserInfo.ToWeChatUser();
+    }
+
+    
 }