实现消息记录功能，包括增删改查和标记已读，优化消息列表展示和未读消息计数

Repository/MessageRecordRepository.cs

@@ -0,0 +1,31 @@
+namespace Repository;
+
+public interface IMessageRecordRepository : IBaseRepository<MessageRecord>
+{
+    Task<(IEnumerable<MessageRecord> List, long Total)> GetPagedListAsync(int pageIndex, int pageSize);
+    Task<bool> MarkAllAsReadAsync();
+}
+
+public class MessageRecordRepository(IFreeSql freeSql) : BaseRepository<MessageRecord>(freeSql), IMessageRecordRepository
+{
+    public async Task<(IEnumerable<MessageRecord> List, long Total)> GetPagedListAsync(int pageIndex, int pageSize)
+    {
+        var list = await FreeSql.Select<MessageRecord>()
+            .OrderByDescending(x => x.CreateTime)
+            .Count(out var total)
+            .Page(pageIndex, pageSize)
+            .ToListAsync();
+            
+        return (list, total);
+    }
+
+    public async Task<bool> MarkAllAsReadAsync()
+    {
+        var affected = await FreeSql.Update<MessageRecord>()
+            .Set(a => a.IsRead, true)
+            .Set(a => a.UpdateTime, DateTime.Now)
+            .Where(a => !a.IsRead)
+            .ExecuteAffrowsAsync();
+        return affected >= 0;
+    }
+}