fix(server): fixes models not being automatically loaded

src/Ngino.Server/Program.cs

@@ -20,6 +20,7 @@ builder.Services.AddSingleton<TunnelHub>();
 builder.Services.AddSingleton<EmbeddingCache>();
 builder.Services.AddSingleton<ManagementStore>();
 builder.Services.AddSingleton<AuthRateLimiter>();
+builder.Services.AddHostedService<KeepaliveService>();
 builder.Services.AddElmah<ElmahCore.MySql.MySqlErrorLog>().Configure<ElmahOptions>(
     options => options.ConnectionString = builder.Configuration.GetConnectionString("ElmahConnection"));