Modernize CLI ergonomics and terminal spacing

[jonathanvdc]

Summary

• add a higher-level command-line API with typed option builders, parse results, and built-in help/version handling
• add logging and transform convenience helpers, and refresh the examples/docs to use the new APIs
• fix terminal separator behavior so nested layout boxes do not introduce leading blank lines or double spacing after diagnostic headers

Testing

• dotnet test Tests/Tests.csproj --configuration Release
• dotnet build Examples/ParseOptions/ParseOptions.csproj --configuration Release
• dotnet build Examples/PrintHelp/PrintHelp.csproj --configuration Release
• dotnet build Examples/LoycInterop/LoycInterop.csproj --configuration Release