feat: 模型列表返回中新增供应商名称字段

在模型列表查询中增加 ProviderName 字段，并在 ModelGetListOutput DTO 中暴露，用于按供应商（如 OpenAI、Anthropic 等）分组展示模型。

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application.Contracts/Dtos/ModelGetListOutput.cs

@@ -48,4 +48,8 @@ public class ModelGetListOutput
     /// 模型图标URL
     /// </summary>
     public string? IconUrl { get; set; }
+    /// <summary>
+    /// 供应商分组名称(如：OpenAI、Anthropic、Google等)
+    /// </summary>
+    public string? ProviderName { get; set; }
 }

Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Application/Services/Chat/AiChatService.cs

@@ -110,7 +110,8 @@ public class AiChatService : ApplicationService
                 Remark = x.Description,
                 IsPremiumPackage = x.IsPremium,
                 ModelApiType = x.ModelApiType,
-                IconUrl = x.IconUrl
+                IconUrl = x.IconUrl,
+                ProviderName = x.ProviderName
             }).ToListAsync();
 
         output.ForEach(x =>