fix(web): 恢复视频继续播放和进度保存

- 将播放器收敛为单个共享实例，避免列表/网格内多个 video ref 导致进度保存失效
- 恢复视频播放器上方的继续播放提示
- 在播放、暂停、拖动、结束、切换页面和离开页面时保存播放位置
- 保留文件浏览分页和排序参数的前端调用

FileShare-Services/Endpoints/AppEndpoints.cs

@@ -2,6 +2,7 @@ using FileShare_Common.Core;
 using FileShare_Services.Core;
 using FileShare_Services.Services.FileLibrary;
 using FileShare_Services.Services.QrCode;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace FileShare_Services.Endpoints
 {
@@ -119,12 +120,15 @@ namespace FileShare_Services.Endpoints
         private static async Task<object?> GetFileStreamAsync(ServiceEndpointContext ctx)
         {
             var sp = ctx.Items["ServiceProvider"] as IServiceProvider;
-            var service = sp?.GetService(typeof(IFileStreamService)) as IFileStreamService;
-            if (service is null) return null;
+            if (sp is null) return null;
 
             if (!int.TryParse(ctx.Query.GetValueOrDefault("id"), out var id) || id <= 0)
                 return null;
 
+            using var scope = sp.CreateScope();
+            var service = scope.ServiceProvider.GetService<IFileStreamService>();
+            if (service is null) return null;
+
             return await service.GetFileStreamAsync(id);
         }