feat(quick): 빠른 변환 간단 옵션 팝업 + 중간 취소 지원

컨텍스트 메뉴에서 형식(MP4/MP3 등) 선택 시 간단 옵션 팝업을 띄우고, 변환 중 취소를 지원한다.

- QuickOptionsWindow(신규): 출력 형식에 맞춘 간단 옵션(영상=품질CRF/해상도/GPU, 오디오=비트레이트,
  이미지=품질) 팝업. '변환'으로 진행, '취소'로 종료, '자세히 옵션…'으로 풀 UI(MainWindow) 전환.
  OptionsViewModel 재사용 → ToConvertOptions()로 변환 옵션 구성.
- App.RunQuickAsync: 변환 전 팝업 표시 + 선택 옵션 적용. ConvertManyAsync에 취소 토큰 전달(이전엔 None이라
  취소 불가였음). 변환 경로는 ShutdownMode=OnExplicitShutdown으로 전환해 **취소/창 닫기 시 ffmpeg를
  종료한 '뒤' 앱을 종료**(고아 프로세스·백그라운드 잔류 방지). 성공 시 결과 창 닫을 때까지 대기.
- QuickProgressWindow: 변환 중 '취소' 버튼 + 창 Closing 시 취소(CancellationTokenSource 주입).
  완료 시 취소 버튼 숨김.

버그 수정: 빠른 변환 진행 창을 닫아도 변환이 백그라운드에서 계속 돌던 문제 해결.
빌드 0/0, 106 테스트 그린, publish 후 팝업/일반 실행 크래시 없이 로드.

src/Everything2Everything.App/App.xaml.cs

@@ -97,19 +97,34 @@ public partial class App : Application
 
     private async Task RunQuickAsync(IReadOnlyList<string> files, string outputExtension)
     {
+        // 빠른 변환 전, 출력 형식에 맞춘 간단 옵션 팝업.
+        // '자세히 옵션…'이면 풀 UI(MainWindow)로 전환, '취소'면 종료, '변환'이면 선택 옵션으로 진행.
+        var optWin = new QuickOptionsWindow(outputExtension, files.Count, Settings);
+        var confirmed = optWin.ShowDialog();
+        if (optWin.OpenFullUi) { ShowConvertDialog(files); return; }
+        if (confirmed != true) { Shutdown(0); return; }
+
+        // 변환 경로 동안은 명시적 종료 모드 — 진행 창을 닫아도 변환을 취소(ffmpeg 종료)한 '뒤' 앱을 종료한다.
+        // (기본 OnLastWindowClose면 창 닫는 즉시 종료가 시작돼 ffmpeg가 고아로 백그라운드에 남는다.)
+        ShutdownMode = System.Windows.ShutdownMode.OnExplicitShutdown;
+
         var logPath = Path.Combine(Path.GetTempPath(), "Everything2Everything_quick.log");
         var log = new System.Text.StringBuilder();
         log.AppendLine($"[{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}] Quick start → {outputExtension}, {files.Count} file(s)");
         foreach (var f in files) log.AppendLine($"  src: {f}");
 
-        var progress = new QuickProgressWindow(files.Count, outputExtension);
+        using var cts = new CancellationTokenSource();
+        var progress = new QuickProgressWindow(files.Count, cts, outputExtension);
+        var closed = new TaskCompletionSource();
+        progress.Closed += (_, _) => closed.TrySetResult();
         progress.Show();
 
         try
         {
-            var options = ConvertOptions.Quick() with { VideoPreferGpu = Settings.Get("video.gpu") != "false" };
+            var options = optWin.Options.ToConvertOptions();
             var reporter = new Progress<ConvertProgress>(p => progress.Report(p));
-            var results = await Engine.ConvertManyAsync(files, outputExtension, options, reporter);
+            var results = await Engine.ConvertManyAsync(
+                files, outputExtension, options, reporter, BatchMode.Independent, cts.Token);
 
             foreach (var r in results)
             {
@@ -120,6 +135,13 @@ public partial class App : Application
             }
 
             progress.Finish(results);
+            await closed.Task; // 결과 창을 사용자가 닫을 때까지 대기(성공 경로)
+        }
+        catch (OperationCanceledException)
+        {
+            // 사용자가 취소(취소 버튼/창 닫기) — ffmpeg는 이미 중단된 뒤 여기에 도달. 진행 창 닫고 종료.
+            log.AppendLine("  CANCELLED by user");
+            try { progress.Close(); } catch { }
         }
         catch (Exception ex)
         {
@@ -132,6 +154,7 @@ public partial class App : Application
         finally
         {
             try { File.WriteAllText(logPath, log.ToString()); } catch { }
+            Shutdown(0); // 모든 경로에서 명시적 종료(백그라운드 잔류·고아 프로세스 방지)
         }
     }
 

src/Everything2Everything.App/Views/QuickOptionsWindow.xaml

@@ -0,0 +1,92 @@
+<ui:FluentWindow x:Class="Everything2Everything.App.Views.QuickOptionsWindow"
+                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                 xmlns:ui="http://schemas.lepo.co/wpfui/2022/xaml"
+                 Title="빠른 변환"
+                 Width="380" SizeToContent="Height"
+                 ResizeMode="NoResize"
+                 ExtendsContentIntoTitleBar="True"
+                 WindowBackdropType="None"
+                 WindowCornerPreference="Round"
+                 WindowStartupLocation="CenterScreen"
+                 UseLayoutRounding="True">
+    <Window.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="FormatShiftTheme.xaml"/>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Window.Resources>
+
+    <Grid Background="{StaticResource FsBgBase}">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="32"/>
+            <RowDefinition Height="*"/>
+        </Grid.RowDefinitions>
+
+        <ui:TitleBar Grid.Row="0" Title="" ShowMaximize="False" ShowMinimize="False"/>
+
+        <StackPanel Grid.Row="1" Margin="24,4,24,20">
+            <TextBlock x:Name="HeaderText" FontSize="16" FontWeight="SemiBold"
+                       Foreground="{StaticResource FsTextPrimary}"
+                       FontFamily="{StaticResource FsFontSans}" Text="변환"/>
+            <TextBlock Margin="0,4,0,0" Style="{StaticResource FsCaptionStyle}"
+                       Text="필요한 옵션만 빠르게 고르고 변환하세요."/>
+
+            <!-- 이미지 품질 (jpg/webp/avif) -->
+            <StackPanel x:Name="ImageQualityPanel" Margin="0,18,0,0" Visibility="Collapsed">
+                <Grid>
+                    <Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="Auto"/></Grid.ColumnDefinitions>
+                    <TextBlock Text="품질" Style="{StaticResource FsCaptionStyle}"/>
+                    <TextBlock Grid.Column="1" FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                               Foreground="{StaticResource FsAccentBlue}"
+                               Text="{Binding Quality, StringFormat={}{0}%}"/>
+                </Grid>
+                <Slider Minimum="1" Maximum="100" Margin="0,4,0,0" Value="{Binding Quality, Mode=TwoWay}"/>
+            </StackPanel>
+
+            <!-- 영상 (간단) -->
+            <StackPanel x:Name="VideoQuickPanel" Margin="0,18,0,0" Visibility="Collapsed">
+                <Grid>
+                    <Grid.ColumnDefinitions><ColumnDefinition Width="*"/><ColumnDefinition Width="Auto"/></Grid.ColumnDefinitions>
+                    <TextBlock Text="품질 (CRF) — 낮을수록 고화질" Style="{StaticResource FsCaptionStyle}"/>
+                    <TextBlock Grid.Column="1" FontFamily="{StaticResource FsFontMono}" FontSize="12"
+                               Foreground="{StaticResource FsAccentBlue}" Text="{Binding Crf}"/>
+                </Grid>
+                <Slider Minimum="0" Maximum="51" Margin="0,4,0,0" Value="{Binding Crf, Mode=TwoWay}"/>
+
+                <TextBlock Text="해상도" Style="{StaticResource FsCaptionStyle}" Margin="0,12,0,4"/>
+                <ComboBox SelectedIndex="{Binding ResolutionIndex, Mode=TwoWay}">
+                    <ComboBoxItem Content="원본"/><ComboBoxItem Content="2160p (4K)"/><ComboBoxItem Content="1440p"/>
+                    <ComboBoxItem Content="1080p"/><ComboBoxItem Content="720p"/><ComboBoxItem Content="480p"/>
+                </ComboBox>
+
+                <CheckBox Margin="0,12,0,0" Content="GPU 하드웨어 가속" IsChecked="{Binding VideoPreferGpu, Mode=TwoWay}"/>
+            </StackPanel>
+
+            <!-- 오디오 (간단) -->
+            <StackPanel x:Name="AudioQuickPanel" Margin="0,18,0,0" Visibility="Collapsed">
+                <TextBlock x:Name="AudioPanelLabel" Text="오디오 비트레이트" Style="{StaticResource FsCaptionStyle}" Margin="0,0,0,4"/>
+                <ComboBox SelectedIndex="{Binding AudioBitrateIndex, Mode=TwoWay}">
+                    <ComboBoxItem Content="96 kbps"/><ComboBoxItem Content="128 kbps"/><ComboBoxItem Content="192 kbps"/>
+                    <ComboBoxItem Content="256 kbps"/><ComboBoxItem Content="320 kbps"/>
+                </ComboBox>
+            </StackPanel>
+
+            <!-- 버튼 -->
+            <Grid Margin="0,22,0,0">
+                <Button HorizontalAlignment="Left" Content="자세히 옵션…"
+                        Style="{StaticResource FsSecondaryButtonStyle}"
+                        Click="OnMoreClick"/>
+                <StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
+                    <Button Content="취소" Margin="0,0,8,0"
+                            Style="{StaticResource FsSecondaryButtonStyle}"
+                            Click="OnCancelClick"/>
+                    <Button Content="변환" Padding="20,6"
+                            Style="{StaticResource FsPrimaryButtonStyle}"
+                            Click="OnConvertClick"/>
+                </StackPanel>
+            </Grid>
+        </StackPanel>
+    </Grid>
+</ui:FluentWindow>

src/Everything2Everything.App/Views/QuickOptionsWindow.xaml.cs

@@ -0,0 +1,64 @@
+using System.Windows;
+using Everything2Everything.App.ViewModels;
+using Everything2Everything.Core;
+using Wpf.Ui.Controls;
+
+namespace Everything2Everything.App.Views;
+
+/// <summary>
+/// 빠른 변환(컨텍스트 메뉴에서 형식 선택) 시 뜨는 간단 옵션 팝업.
+/// 출력 형식에 맞춘 핵심 옵션만 노출하고, '자세히 옵션…'은 풀 UI(MainWindow)로 넘어간다.
+/// </summary>
+public partial class QuickOptionsWindow : FluentWindow
+{
+    /// <summary>팝업이 바인딩하는 옵션 뷰모델. 변환 확정 시 ToConvertOptions()로 사용.</summary>
+    public OptionsViewModel Options { get; } = new();
+
+    /// <summary>사용자가 '자세히 옵션…'을 눌러 풀 UI로 넘어가길 원하는가.</summary>
+    public bool OpenFullUi { get; private set; }
+
+    public QuickOptionsWindow(string outputExtension, int fileCount, ISettingsStore settings)
+    {
+        Options.VideoPreferGpu = settings.Get("video.gpu") != "false";
+        DataContext = Options;
+        InitializeComponent();
+        ConfigureForFormat(outputExtension, fileCount);
+    }
+
+    private void ConfigureForFormat(string ext, int count)
+    {
+        ext = ext.ToLowerInvariant();
+        var label = ext.TrimStart('.').ToUpperInvariant();
+        HeaderText.Text = count > 1 ? $"{label}(으)로 변환 · {count}개 파일" : $"{label}(으)로 변환";
+
+        var isVideo = ext is ".mp4" or ".mkv" or ".webm" or ".mov" or ".avi";
+        var isLossyAudio = ext is ".mp3" or ".aac" or ".m4a" or ".opus" or ".ogg";
+        var isImageQuality = ext is ".jpg" or ".jpeg" or ".webp" or ".avif";
+
+        VideoQuickPanel.Visibility = isVideo ? Visibility.Visible : Visibility.Collapsed;
+        AudioQuickPanel.Visibility = (isVideo || isLossyAudio) ? Visibility.Visible : Visibility.Collapsed;
+        ImageQualityPanel.Visibility = isImageQuality ? Visibility.Visible : Visibility.Collapsed;
+
+        // 영상의 오디오 트랙임을 구분
+        if (isVideo) AudioPanelLabel.Text = "오디오 비트레이트";
+    }
+
+    private void OnConvertClick(object sender, RoutedEventArgs e)
+    {
+        DialogResult = true;
+        Close();
+    }
+
+    private void OnCancelClick(object sender, RoutedEventArgs e)
+    {
+        DialogResult = false;
+        Close();
+    }
+
+    private void OnMoreClick(object sender, RoutedEventArgs e)
+    {
+        OpenFullUi = true;
+        DialogResult = false;
+        Close();
+    }
+}

src/Everything2Everything.App/Views/QuickProgressWindow.xaml

@@ -8,7 +8,8 @@
                  WindowBackdropType="Mica"
                  WindowCornerPreference="Round"
                  WindowStartupLocation="CenterScreen"
-                 ResizeMode="NoResize">
+                 ResizeMode="NoResize"
+                 Closing="OnWindowClosing">
     <Grid>
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto"/>
@@ -41,13 +42,24 @@
                    HorizontalAlignment="Center" VerticalAlignment="Center"
                    RenderOptions.BitmapScalingMode="HighQuality"
                    Source="pack://application:,,,/Assets/illus-done.png"/>
-            <StackPanel Grid.Row="4" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,12,0,0">
+            <Grid Grid.Row="4" Margin="0,12,0,0">
-                <ui:Button x:Name="OpenFolderButton" Content="결과 폴더 열기"
+                <Grid.ColumnDefinitions>
-                           Icon="{ui:SymbolIcon Folder24}"
+                    <ColumnDefinition Width="Auto"/>
-                           Click="OnOpenFolderClick" IsEnabled="False" Margin="0,0,8,0"/>
+                    <ColumnDefinition Width="*"/>
-                <ui:Button x:Name="CloseButton" Content="닫기" Click="OnCloseClick"
+                    <ColumnDefinition Width="Auto"/>
-                           Appearance="Primary" IsEnabled="False"/>
+                </Grid.ColumnDefinitions>
-            </StackPanel>
+                <!-- 변환 중 취소 (완료되면 숨김) -->
+                <ui:Button x:Name="CancelButton" Grid.Column="0" Content="취소"
+                           Icon="{ui:SymbolIcon Dismiss24}"
+                           Click="OnCancelClick" HorizontalAlignment="Left"/>
+                <StackPanel Grid.Column="2" Orientation="Horizontal" HorizontalAlignment="Right">
+                    <ui:Button x:Name="OpenFolderButton" Content="결과 폴더 열기"
+                               Icon="{ui:SymbolIcon Folder24}"
+                               Click="OnOpenFolderClick" IsEnabled="False" Margin="0,0,8,0"/>
+                    <ui:Button x:Name="CloseButton" Content="닫기" Click="OnCloseClick"
+                               Appearance="Primary" IsEnabled="False"/>
+                </StackPanel>
+            </Grid>
         </Grid>
     </Grid>
 </ui:FluentWindow>

src/Everything2Everything.App/Views/QuickProgressWindow.xaml.cs

@@ -7,11 +7,14 @@ namespace Everything2Everything.App.Views;
 public partial class QuickProgressWindow : FluentWindow
 {
     private readonly int _total;
+    private readonly CancellationTokenSource _cts;
+    private bool _finished;
     private string? _firstSuccessOutput;
 
-    public QuickProgressWindow(int total, string? outputExtension = null)
+    public QuickProgressWindow(int total, CancellationTokenSource cts, string? outputExtension = null)
     {
         _total = total;
+        _cts = cts;
         InitializeComponent();
 
         var label = string.IsNullOrWhiteSpace(outputExtension)
@@ -39,6 +42,9 @@ public partial class QuickProgressWindow : FluentWindow
     {
         if (!CheckAccess()) { Dispatcher.Invoke(() => Finish(results)); return; }
 
+        _finished = true;
+        CancelButton.Visibility = Visibility.Collapsed;
+
         var success = results.Count(r => r.Status == ConvertStatus.Success);
         var skipped = results.Count(r => r.Status == ConvertStatus.Skipped);
         var failed = results.Count(r => r.Status == ConvertStatus.Failed);
@@ -92,6 +98,23 @@ public partial class QuickProgressWindow : FluentWindow
 
     private void OnCloseClick(object sender, RoutedEventArgs e) => Close();
 
+    private void OnCancelClick(object sender, RoutedEventArgs e)
+    {
+        try { _cts.Cancel(); } catch { }
+        CancelButton.IsEnabled = false;
+        CancelButton.Content = "취소 중…";
+        StatusText.Text = "취소 중…";
+    }
+
+    /// <summary>변환 중에 창을 닫으면 변환을 취소한다(백그라운드 잔류·고아 ffmpeg 방지).</summary>
+    private void OnWindowClosing(object? sender, System.ComponentModel.CancelEventArgs e)
+    {
+        if (!_finished)
+        {
+            try { _cts.Cancel(); } catch { }
+        }
+    }
+
     private static void OpenInExplorer(string path)
     {
         try