Firefox_Secure/FirefoxLauncher.cs

using System;
using System.Diagnostics;
using System.IO;

internal static class FirefoxLauncher
{
    private static int Main()
    {
        string baseDir = AppDomain.CurrentDomain.BaseDirectory;
        string scriptPath = Path.Combine(baseDir, "FirefoxSessionVault.ps1");

        if (!File.Exists(scriptPath))
        {
            return 2;
        }

        var startInfo = new ProcessStartInfo
        {
            FileName = "powershell.exe",
            Arguments = "-NoProfile -Sta -ExecutionPolicy Bypass -WindowStyle Hidden -File \"" + scriptPath + "\" -Mode Toggle",
            WorkingDirectory = baseDir,
            UseShellExecute = false,
            CreateNoWindow = true,
            WindowStyle = ProcessWindowStyle.Hidden
        };

        Process.Start(startInfo);
        return 0;
    }
}