Add lightweight ASP.NET Core Todo API sample

[balajibashyam]

Summary

Adds a minimal .NET 10 companion sample for the ASP.NET Core Fundamentals: Build Web APIs on .NET 8 tutorial.

What's included

• New sample: aspnet-core/build-web-api-dotnet-8/ — 6 files

  • Minimal API route group at /api/todos
  • In-memory repository registered through DI
  • GET, POST, PUT, DELETE with correct HTTP semantics
  • Route constraints ({id:int:min(1)})
  • Request-body binding and validation
  • X-Request-Id middleware
  • /health endpoint
  • 7 integration tests using WebApplicationFactory<Program>

• Root README: New sample row in the table + updated repository structure

• GitHub Actions: New test-web-api-fundamentals job in the shared workflow; path filters updated

Deliberately omitted (stays in the full tutorial)

Controllers, EF Core, SQLite, migrations, JWT authentication, authorization, CORS, caching, rate limiting, Swagger/OpenAPI, Docker, cloud deployment, production storage.

Versions

• .NET SDK: 10.0.302
• Microsoft.AspNetCore.Mvc.Testing: 10.0.10
• Microsoft.NET.Test.Sdk: 18.8.1
• xunit.v3: 3.2.2
• xunit.runner.visualstudio: 3.1.5

Validation

• dotnet restore — passed
• dotnet build --configuration Release — passed (0 errors, 0 warnings)
• dotnet test --configuration Release — passed (7/7)
• Runtime validation (curl) — all endpoints verified
• Security scan — clean