v1.15 — PowerShell edition + repo restructure

- New powershell/InstaSoftOfficeTool.ps1: single-file WPF GUI version
  - Same Fluent Design UI, no compilation needed
  - Runs on any Windows 7+ with PowerShell 5.1 (built-in)
  - Chrome won't flag .ps1 files as "rarely downloaded"
  - Auto-elevates to admin
- Moved C# source to src/ subfolder
- Updated .gitignore for nested bin/obj folders

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Pages/ConfirmDialog.xaml.cs

@@ -1,75 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Input;
-using System.Windows.Media;
-
-namespace InstaSoftOfficeTool.Pages
-{
-    public partial class ConfirmDialog : UserControl
-    {
-        private TaskCompletionSource<bool> _tcs;
-
-        public ConfirmDialog()
-        {
-            InitializeComponent();
-        }
-
-        public Task<bool> ShowAsync(string title, string message,
-            string confirmText = "Igen", string cancelText = "M\u00e9gse",
-            DialogType type = DialogType.Warning)
-        {
-            DialogTitle.Text = title;
-            DialogMessage.Text = message;
-            BtnConfirm.Content = confirmText;
-            BtnCancel.Content = cancelText;
-
-            switch (type)
-            {
-                case DialogType.Warning:
-                    DialogIcon.Text = "\uE7BA";
-                    DialogIcon.Foreground = (Brush)FindResource("WarningBrush");
-                    break;
-                case DialogType.Question:
-                    DialogIcon.Text = "\uE9CE";
-                    DialogIcon.Foreground = (Brush)FindResource("AccentBrush");
-                    break;
-                case DialogType.Error:
-                    DialogIcon.Text = "\uE711";
-                    DialogIcon.Foreground = (Brush)FindResource("ErrorBrush");
-                    break;
-            }
-
-            Visibility = Visibility.Visible;
-            _tcs = new TaskCompletionSource<bool>();
-            return _tcs.Task;
-        }
-
-        private void BtnConfirm_Click(object sender, RoutedEventArgs e)
-        {
-            Visibility = Visibility.Collapsed;
-            _tcs?.TrySetResult(true);
-        }
-
-        private void BtnCancel_Click(object sender, RoutedEventArgs e)
-        {
-            Visibility = Visibility.Collapsed;
-            _tcs?.TrySetResult(false);
-        }
-
-        private void Backdrop_MouseDown(object sender, MouseButtonEventArgs e)
-        {
-            // click outside = cancel
-            Visibility = Visibility.Collapsed;
-            _tcs?.TrySetResult(false);
-        }
-    }
-
-    public enum DialogType
-    {
-        Warning,
-        Question,
-        Error
-    }
-}