Attribute.cs

public enum EReadOnlyType {
    FULLY_DISABLED,
    EDITABLE_RUNTIME,
    EDITABLE_EDITOR,
}

public class ReadOnlyAttribute : UnityEngine.PropertyAttribute {
        
    public readonly EReadOnlyType runtimeOnly;

    public ReadOnlyAttribute(EReadOnlyType runtimeOnly = EReadOnlyType.FULLY_DISABLED)
    {
        this.runtimeOnly = runtimeOnly;
    }
}

public class BeginReadOnlyAttribute : UnityEngine.PropertyAttribute { }

public class EndReadOnlyAttribute : UnityEngine.PropertyAttribute { }