Add test endpoint for middleware validation tests

backend/WorkClub.Api/Program.cs

@@ -223,6 +223,10 @@ app.MapGet("/weatherforecast", () =>
 })
 .WithName("GetWeatherForecast");
 
+// Simple test endpoint for middleware validation tests
+app.MapGet("/api/test", () => Results.Ok(new { message = "Test endpoint" }))
+    .RequireAuthorization();
+
 app.MapGet("/api/debug/claims", (HttpContext context) =>
 {
     var claims = context.User.Claims.Select(c => new { c.Type, c.Value }).ToList();