Add project files.

WebApi/Program.cs

@@ -0,0 +1,24 @@
+using Scalar.AspNetCore;
+using WebApi.Endpoints;
+using WebApi.Extensions;
+
+var builder = WebApplication.CreateBuilder();
+
+builder.Services
+    .AddApplicationServices(builder.Configuration)
+    .AddObservability(builder.Configuration);
+
+var app = builder.Build();
+
+if (app.Environment.IsDevelopment())
+{
+    app.MapOpenApi();
+    app.MapScalarApiReference();
+}
+
+app
+    .MapPlayListEndpoints()
+    .MapTrackEndpoints()
+    .MapUserEndpoints();
+
+app.Run();