Upgrade BooksAPI to .NET 10 and add Docker Compose support

[edwardgnt]

Summary

• Upgraded BooksAPI from .NET 9 to .NET 10
• Added Docker Compose support for the API and SQL Server
• Added SQL Server initialization script for BooksDb and seed data
• Updated local configuration to avoid old SQLEXPRESS dependency
• Updated GitHub Actions CI for .NET 10 and SQL Server-backed integration tests
• Updated README documentation for Docker setup and SSMS access

Validation

• Ran dotnet build
• Ran dotnet test
• Verified Docker SQL Server login
• Verified database initialization script creates BooksDb and seed data
• Verified API container responds at http://localhost:8080/api/books
• Verified SQL Server data is visible from SSMS through localhost,14333