feat: implement cross-device reading progress synchronization using SignalR and remove legacy quiz generation services.

src/NexusReader.Web.New/Program.cs

@@ -31,6 +31,8 @@ builder.Services.AddServerSideBlazor()
     {
         options.DetailedErrors = true;
     });
+builder.Services.AddSignalR();
+builder.Services.AddHttpContextAccessor();
 
 builder.Services.AddScoped<IPlatformService, WebPlatformService>();
 builder.Services.AddScoped<INativeStorageService, NexusReader.UI.Shared.Services.WebStorageService>();
@@ -41,6 +43,7 @@ builder.Services.AddScoped<IReaderNavigationService, ReaderNavigationService>();
 builder.Services.AddScoped<IKnowledgeGraphService, KnowledgeGraphService>();
 builder.Services.AddScoped<IReaderInteractionService, ReaderInteractionService>();
 builder.Services.AddScoped<KnowledgeCoordinator>();
+builder.Services.AddScoped<ISyncService, SyncService>();
 
 builder.Services.AddHttpClient("NexusAPI", client => 
 {
@@ -181,6 +184,7 @@ app.UseAntiforgery();
 app.UseAuthentication();
 app.UseAuthorization();
 app.MapStaticAssets();
+app.MapHub<NexusReader.Infrastructure.RealTime.SyncHub>("/synchub");
 
 // API endpoint for WASM client to fetch EPUB content
 app.MapGet("/api/epub/{index}", async (int index, IEpubService epubService) =>