Enhancement: Add dark mode option with default detection of system theme

[leonidasIIV]

Please add a Dark mode theme for the application with option for user to select theme. Theme selections could be as follows:

• Auto: (default): Uses the System Theme
• Light: Uses the Light Mode Theme
• Dar: Uses the Dark Mode Theme

Several WPF Theme libraries exist for use if third-party libraries/code is acceptable. Including, but not limited to:

• Modern WPF
• WPF Dark Theme
• Dark Net
• Syncfusion Themes Material Dark WPF

[tylercamp]

I looked into this a few times since I started and all the WPF themes I found either had usability, completeness, or licensing issues

I don’t have the experience to fill in gaps (missing controls/states) in the themes and don’t want to dump a bunch of time into it

I considered porting to Avalonia, which has built in dark themes and generally more useful controls available, but the EXE size jumped to 100MB (back when I had asset compression still enabled) and I was having issues with the WYSIWYG editor in Visual Studio

I’d really like to have a dark theme but it just hasn’t been worth the effort

I’m ok with leaving this open if someone else wants to try their hand at updating

[tylercamp]

Looking into these again, skipping "WPF Dark Theme" since all of the options had readability issues due to low contrast when I last checked, skipping "Modern WPF" since all the whitespace messes with the layouts

Syncfusion

Syncfusion Blend:

Material3 Light:

Material3 Dark:

Material Light:

Material Dark:

Metro:

Fluent Light:

Fluent Dark:

System Theme: (I had dark system theme in Windows at the time)

Windows 11 Light:

Windows 11 Dark:

Adonis

Dark:

Light:

.NET 9 Fluent

(Build into .NET 9)

Dark:

Light: