fix: Past Results 폴더 버튼이 출력 파일을 select하도록 변경

- HistoryEntry에 OutputPaths (nullable list) 추가, PrimaryOutputPath 헬퍼
- HistoryRow에 OutputPath + RevealPath (output 우선, fallback to source)
- AddToHistory 호출 시 result.OutputPaths.ToList() 전달
- XAML 폴더 버튼 Tag를 RevealPath로, ToolTip '출력 파일이 있는 폴더 열기'

이전 history.jsonl은 OutputPaths 없이 저장됨 — 새 변환부터 출력 select

src/Everything2Everything.App/Views/MainWindow.xaml

@@ -549,8 +549,8 @@
                                                                     BorderThickness="0"
                                                                     Padding="6"
                                                                     Click="OnOpenFolderClick"
-                                                                    Tag="{Binding SourcePath}"
-                                                                    ToolTip="원본 폴더 열기">
+                                                                    Tag="{Binding RevealPath}"
+                                                                    ToolTip="출력 파일이 있는 폴더 열기">
                                                                 <Path Width="14" Height="14" Stretch="Uniform"
                                                                       Stroke="{StaticResource FsTextTertiary}"
                                                                       StrokeThickness="2"

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

@@ -557,7 +557,8 @@ public partial class MainWindow : Wpf.Ui.Controls.FluentWindow
                     OutputCount: result.OutputPaths.Count,
                     MetaLine: item.MetaLine,
                     Status: result.Status,
-                    Message: result.Message));
+                    Message: result.Message,
+                    OutputPaths: result.OutputPaths.ToList()));
 
                 _activeQueue.Remove(item);
             }
@@ -1100,8 +1101,11 @@ public sealed record HistoryRow(
     string SizeText,
     string SavingsText,
     string SourcePath,
+    string? OutputPath = null,
     long SavingsBytes = 0)
 {
+    public string RevealPath => OutputPath ?? SourcePath;
+
     public static HistoryRow From(HistoryEntry e)
     {
         var ext = Path.GetExtension(e.SourcePath).TrimStart('.').ToLowerInvariant();
@@ -1116,6 +1120,7 @@ public sealed record HistoryRow(
             SizeText: MainWindow.HumanizeBytes(e.SourceSizeBytes),
             SavingsText: $"{arrow} {MainWindow.HumanizeBytes(Math.Abs(saved))}",
             SourcePath: e.SourcePath,
+            OutputPath: e.PrimaryOutputPath,
             SavingsBytes: saved);
     }
 }

src/Everything2Everything.Core/HistoryStore.cs

@@ -11,11 +11,14 @@ public sealed record HistoryEntry(
     int OutputCount,
     string? MetaLine,
     ConvertStatus Status,
-    string? Message)
+    string? Message,
+    IReadOnlyList<string>? OutputPaths = null)
 {
     public long SavingsBytes => SourceSizeBytes - OutputSizeBytes;
 
     public DateOnly Date => DateOnly.FromDateTime(Timestamp);
+
+    public string? PrimaryOutputPath => OutputPaths is { Count: > 0 } list ? list[0] : null;
 }
 
 public sealed class HistoryStore