Fixing bugs and problems - #25

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, actions/upload-artifact@v4, nick-fields/retry@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

The field 'TreeViewPanel._isAnimatingColumns' is assigned but its value is never used

The event 'InternalCommand.CanExecuteChanged' is never used

Possible null reference argument for parameter 'item' in 'Control? ItemsControl.ContainerFromItem(object item)'.

Possible null reference argument for parameter 'item' in 'Control? ItemsControl.ContainerFromItem(object item)'.

Possible null reference argument for parameter 'container' in 'int ItemsControl.IndexFromContainer(Control container)'.

Possible null reference argument for parameter 'name' in 'Theme.Theme(string name, ThemeVariant? themeVariant)'.

The type 'GlyphTypeface' includes the ref like property, field or constructor parameter 'SupportedLanguages'. No source code will be generated for the property, field or constructor. (https://learn.microsoft.com/dotnet/fundamentals/syslib-diagnostics/syslib1225)

The type 'GlyphTypeface' includes the ref like property, field or constructor parameter 'DesignLanguages'. No source code will be generated for the property, field or constructor. (https://learn.microsoft.com/dotnet/fundamentals/syslib-diagnostics/syslib1225)

Nullability of reference types in value of type '(string FilePath, List<string> Keys, bool Success, string? Error)' doesn't match target type '(string FilePath, List<string> Keys, bool Success, string Error)'.