Add ToolTips resource dictionary and enhance AboutView with new styles - #59

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-dotnet@v4, microsoft/setup-msbuild@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Dereference of a possibly null reference.

Converting null literal or possible null value to non-nullable type.

Unboxing a possibly null value.

Unreachable code detected

Non-nullable event 'CanExecuteChanged' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the event as nullable.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of reference types in type of 'event EventHandler AsyncRelayCommand.CanExecuteChanged' doesn't match implicitly implemented member 'event EventHandler? ICommand.CanExecuteChanged'.

Nullability of reference types in type of parameter 'parameter' doesn't match implemented member 'bool ICommand.CanExecute(object? parameter)' (possibly because of nullability attributes).