**Initialize React Vite project with basic setup**

Add initial project structure including React, Vite, TailwindCSS, and Syncfusion dependencies. Configure tooling with ESLint, TypeScript, and Tailwind plugins. Set up `.gitignore`, Syncfusion themes, and example components for demonstration purposes.

Api/SignalR/UserProvider.cs

@@ -0,0 +1,14 @@
+using Microsoft.AspNetCore.SignalR;
+
+namespace Api.SignalR
+{
+    public class UserProvider : IUserIdProvider
+    {
+        public string GetUserId(HubConnectionContext connection)
+        {
+            // Extract the "userId" query parameter from the HTTP context.
+            var httpContext = connection.GetHttpContext();
+            return httpContext?.Request.Query["userId"].FirstOrDefault();
+        }
+    }
+}