feat(ui): add copy-last-40-lines button to log visualizer

src/ClaudeDo.Localization/locales/de.json

@@ -310,6 +310,10 @@
       "refresh": "Aktualisieren",
       "empty": "Keine Logs in den letzten 30 Minuten.",
       "count": "{0} Einträge",
+      "copyLast": "Letzte 40 kopieren",
+      "copyLastTooltip": "Kopiert die letzten 40 sichtbaren Zeilen in die Zwischenablage",
+      "copied": "{0} Zeilen kopiert",
+      "copyFailed": "Kopieren fehlgeschlagen",
       "footerHint": "logs",
       "openTooltip": "Aktuelle Worker-Logs anzeigen"
     },

src/ClaudeDo.Localization/locales/en.json

@@ -311,7 +311,11 @@
       "empty": "No logs in the last 30 minutes.",
       "count": "{0} entries",
       "footerHint": "logs",
-      "openTooltip": "View recent worker logs"
+      "openTooltip": "View recent worker logs",
+      "copyLast": "Copy last 40",
+      "copyLastTooltip": "Copy the last 40 visible lines to the clipboard",
+      "copied": "{0} lines copied",
+      "copyFailed": "Copy failed"
     },
     "about": {
       "title": "ABOUT",

src/ClaudeDo.Ui/ViewModels/Modals/LogVisualizerViewModel.cs

@@ -3,6 +3,9 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
 using System.Threading.Tasks;
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Input.Platform;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Ui.Localization;
 using ClaudeDo.Ui.Services;
@@ -18,7 +21,10 @@ namespace ClaudeDo.Ui.ViewModels.Modals;
 /// </summary>
 public sealed partial class LogVisualizerViewModel : ViewModelBase
 {
+    private const int CopyLastCount = 40;
+
     private readonly IWorkerClient _worker;
+    private readonly Func<string, Task<bool>> _copyToClipboard;
     private IReadOnlyList<WorkerLogEntry> _all = Array.Empty<WorkerLogEntry>();
 
     public ObservableCollection<LogVisualizerRow> Rows { get; } = new();
@@ -28,7 +34,14 @@ public sealed partial class LogVisualizerViewModel : ViewModelBase
 
     public Action? CloseAction { get; set; }
 
-    public LogVisualizerViewModel(IWorkerClient worker) => _worker = worker;
+    public LogVisualizerViewModel(IWorkerClient worker) : this(worker, CopyToClipboardAsync) { }
+
+    internal LogVisualizerViewModel(IWorkerClient worker, Func<string, Task<bool>> copyToClipboard)
+    {
+        _worker = worker;
+        _copyToClipboard = copyToClipboard;
+        Rows.CollectionChanged += (_, _) => CopyLastCommand.NotifyCanExecuteChanged();
+    }
 
     [RelayCommand]
     public async Task RefreshAsync()
@@ -53,6 +66,33 @@ public sealed partial class LogVisualizerViewModel : ViewModelBase
     }
 
     [RelayCommand] private void Close() => CloseAction?.Invoke();
+
+    private bool CanCopyLast() => Rows.Count > 0;
+
+    [RelayCommand(CanExecute = nameof(CanCopyLast))]
+    private async Task CopyLastAsync()
+    {
+        var count = Math.Min(Rows.Count, CopyLastCount);
+        var ok = await _copyToClipboard(BuildCopyText());
+        StatusText = ok
+            ? Loc.T("modals.logVisualizer.copied", count)
+            : Loc.T("modals.logVisualizer.copyFailed");
+    }
+
+    internal string BuildCopyText() =>
+        string.Join('\n', Rows.Take(CopyLastCount).Reverse()
+            .Select(r => $"{r.Time}  {r.Level.ToString().ToUpperInvariant()}  {r.Message}"));
+
+    private static async Task<bool> CopyToClipboardAsync(string text)
+    {
+        if (Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop &&
+            desktop.MainWindow?.Clipboard is { } clipboard)
+        {
+            try { await clipboard.SetTextAsync(text); return true; }
+            catch { return false; }
+        }
+        return false;
+    }
 }
 
 public sealed record LogVisualizerRow(string Time, string Message, WorkerLogLevel Level);

src/ClaudeDo.Ui/Views/Modals/LogVisualizerView.axaml

@@ -22,7 +22,7 @@
   <ctl:ModalShell Title="{loc:Tr modals.logVisualizer.title}" CloseCommand="{Binding CloseCommand}">
     <DockPanel LastChildFill="True">
       <!-- Toolbar: filter · status · refresh -->
-      <Grid DockPanel.Dock="Top" ColumnDefinitions="Auto,*,Auto" Margin="14,10">
+      <Grid DockPanel.Dock="Top" ColumnDefinitions="Auto,*,Auto,Auto" Margin="14,10">
         <CheckBox Grid.Column="0"
                   Content="{loc:Tr modals.logVisualizer.warnErrorOnly}"
                   IsChecked="{Binding WarnErrorOnly}"
@@ -31,7 +31,11 @@
                    Text="{Binding StatusText}"
                    HorizontalAlignment="Center" VerticalAlignment="Center"
                    Foreground="{DynamicResource TextMuteBrush}"/>
-        <Button Grid.Column="2" Classes="btn"
+        <Button Grid.Column="2" Classes="btn" Margin="0,0,8,0"
+                Content="{loc:Tr modals.logVisualizer.copyLast}"
+                ToolTip.Tip="{loc:Tr modals.logVisualizer.copyLastTooltip}"
+                Command="{Binding CopyLastCommand}"/>
+        <Button Grid.Column="3" Classes="btn"
                 Content="{loc:Tr modals.logVisualizer.refresh}"
                 Command="{Binding RefreshCommand}"/>
       </Grid>

tests/ClaudeDo.Ui.Tests/ViewModels/LogVisualizerViewModelTests.cs

@@ -85,4 +85,95 @@ public class LogVisualizerViewModelTests
 
         Assert.Equal(new[] { "newest", "middle", "oldest" }, vm.Rows.Select(r => r.Message));
     }
+
+    [Fact]
+    public async Task CopyLast_orders_chronologically_oldest_first()
+    {
+        var t0 = new DateTime(2026, 6, 23, 8, 0, 0, DateTimeKind.Utc);
+        var vm = new LogVisualizerViewModel(new FakeClient(new[]
+        {
+            E(WorkerLogLevel.Info, "oldest", t0),
+            E(WorkerLogLevel.Warn, "middle", t0.AddMinutes(1)),
+            E(WorkerLogLevel.Error, "newest", t0.AddMinutes(2)),
+        }));
+        await vm.RefreshAsync();
+
+        var text = vm.BuildCopyText();
+
+        var lines = text.Split('\n');
+        Assert.Equal(3, lines.Length);
+        Assert.EndsWith("INFO  oldest", lines[0]);
+        Assert.EndsWith("WARN  middle", lines[1]);
+        Assert.EndsWith("ERROR  newest", lines[2]);
+    }
+
+    [Fact]
+    public async Task CopyLast_caps_at_40_most_recent_entries()
+    {
+        var t0 = new DateTime(2026, 6, 23, 8, 0, 0, DateTimeKind.Utc);
+        var entries = Enumerable.Range(0, 50)
+            .Select(i => E(WorkerLogLevel.Info, $"line{i}", t0.AddMinutes(i)))
+            .ToArray();
+        var vm = new LogVisualizerViewModel(new FakeClient(entries));
+        await vm.RefreshAsync();
+
+        var lines = vm.BuildCopyText().Split('\n');
+
+        Assert.Equal(40, lines.Length);
+        Assert.EndsWith("line10", lines[0]);
+        Assert.EndsWith("line49", lines[^1]);
+    }
+
+    [Fact]
+    public async Task CopyLast_respects_active_warn_error_filter()
+    {
+        var t0 = new DateTime(2026, 6, 23, 8, 0, 0, DateTimeKind.Utc);
+        var vm = new LogVisualizerViewModel(new FakeClient(new[]
+        {
+            E(WorkerLogLevel.Info, "skipped", t0),
+            E(WorkerLogLevel.Warn, "kept", t0.AddMinutes(1)),
+        }));
+        await vm.RefreshAsync();
+        vm.WarnErrorOnly = true;
+
+        var lines = vm.BuildCopyText().Split('\n');
+
+        Assert.Single(lines);
+        Assert.EndsWith("WARN  kept", lines[0]);
+    }
+
+    [Fact]
+    public async Task CopyLastCommand_disabled_when_no_rows()
+    {
+        var vm = new LogVisualizerViewModel(new FakeClient(Array.Empty<WorkerLogEntry>()));
+        await vm.RefreshAsync();
+
+        Assert.False(vm.CopyLastCommand.CanExecute(null));
+    }
+
+    [Fact]
+    public async Task CopyLastCommand_copies_and_reports_count_on_success()
+    {
+        string? copied = null;
+        var vm = new LogVisualizerViewModel(new FakeClient(new[] { E(WorkerLogLevel.Info, "a") }),
+            text => { copied = text; return Task.FromResult(true); });
+        await vm.RefreshAsync();
+
+        await vm.CopyLastCommand.ExecuteAsync(null);
+
+        Assert.EndsWith("INFO  a", copied);
+        Assert.Contains("1", vm.StatusText);
+    }
+
+    [Fact]
+    public async Task CopyLastCommand_reports_failure_when_clipboard_unavailable()
+    {
+        var vm = new LogVisualizerViewModel(new FakeClient(new[] { E(WorkerLogLevel.Info, "a") }),
+            _ => Task.FromResult(false));
+        await vm.RefreshAsync();
+
+        await vm.CopyLastCommand.ExecuteAsync(null);
+
+        Assert.False(string.IsNullOrEmpty(vm.StatusText));
+    }
 }