Configure API to serve SPA, integrate SignalR, and update build paths

API/Program.cs

@@ -1,8 +1,15 @@
 var builder = WebApplication.CreateBuilder(args);
 
+// Serve frontend from wwwroot at solution root
+var webRootPath = Path.GetFullPath(Path.Combine(builder.Environment.ContentRootPath, "..", "wwwroot"));
+Directory.CreateDirectory(webRootPath);
+builder.Environment.WebRootPath = webRootPath;
+builder.WebHost.UseWebRoot(webRootPath);
+
 // Add services to the container.
 
 builder.Services.AddControllers();
+builder.Services.AddSignalR();
 builder.Services.AddOpenApi();
 builder.Services.AddSwaggerGen();
 
@@ -18,8 +25,14 @@ if (app.Environment.IsDevelopment())
 
 app.UseHttpsRedirection();
 
+app.UseStaticFiles();
+
 app.UseAuthorization();
 
 app.MapControllers();
+app.MapHub<API.Controllers.GameController>("/api/game");
+
+// SPA fallback: serve index.html for routes not matched by API or static files
+app.MapFallbackToFile("index.html");
 
 app.Run();