C# .NET using reflection, integer underflow, and a touch of LINQ. Should work for all integer types. (edit: also works with char values)

// this increments i
private static T Increment<T>(T i)
{
    var valType = typeof(T);
    var maxField = valType.GetField("MaxValue");
    var minField = valType.GetField("MinValue");
    if (maxField != null)
    {
        T maxValue = (T)maxField.GetValue(i);
        T minValue = (T)minField.GetValue(i);

        var methods = valType.GetTypeInfo().DeclaredMethods;
        var subMethod = methods.Where(m => m.Name.EndsWith("op_Subtraction")).First();
               
        T interim = (T)subMethod.Invoke(
            null,
            [i, maxValue]);

        return (T)subMethod.Invoke(
            null, 
            [interim, minValue]);
    }
    throw new ArgumentException("Not incrementable.");
}

When I initially set up my media server I went with Jellyfin over Plex mostly because the idea of having to create an account on an external service to use software I was hosting myself rubbed me the wrong way. Since then the more learn about Plex the more baffled I am that anyone chooses to use it at all.