feat(ui): Mission Control Recent Sessions mit verschachtelten Handoffs

Neue Tabelle mission_control_sessions (Migration AddMissionControlSessions), befuellt vom
InteractiveLaunchSpecService bei Task-, Ad-hoc- und Handoff-Kacheln. Flyout im Mission-Control-Header
listet die letzten 14 Tage / 50 Sessions, Handoffs eingerueckt unter ihrer Ursprungs-Session, mit
Fortsetzen (--resume im gespeicherten cwd) und Brief anzeigen.

src/ClaudeDo.Ui/Design/Tokens.axaml

@@ -158,6 +158,7 @@
   <Thickness x:Key="IslandHeaderPadding">18,16,18,12</Thickness>
   <Thickness x:Key="IslandBodyPadding">14</Thickness>
   <Thickness x:Key="WindowBodyPadding">14</Thickness>
+  <Thickness x:Key="NestedRowIndent">18,0,0,0</Thickness>  <!-- SpaceXl: a child row under its parent -->
 
   <!-- ============================================================ -->
   <!-- CORNERS & BORDERS                                            -->

src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs

@@ -141,6 +141,8 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, string paneId, CancellationToken ct = default);
     /// <summary>Launch spec for the fresh session a tile hands off to after handoff_session.</summary>
     Task<LaunchSpec> GetSessionHandoffLaunchSpecAsync(string paneId, string cwd, string briefPath, string? taskId, CancellationToken ct = default);
+    /// <summary>Launch spec resuming a recorded Mission Control session in its cwd, as tile paneId.</summary>
+    Task<LaunchSpec> GetResumeSessionLaunchSpecAsync(string sessionId, string paneId, CancellationToken ct = default);
     /// <summary>Launch spec for an embedded ConPTY "merge helper" session that drives the given
     /// tasks to a merged/Done state. listId scopes the session (and cwd) to that list.
     /// handlerTaskId (from CreateMergeHelperTaskAsync) is rendered into the brief so the session

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -632,6 +632,9 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<LaunchSpec> GetSessionHandoffLaunchSpecAsync(string paneId, string cwd, string briefPath, string? taskId, CancellationToken ct = default)
         => await InvokeTimedAsync<LaunchSpec>("GetSessionHandoffLaunchSpec", () => _hub.InvokeAsync<LaunchSpec>("GetSessionHandoffLaunchSpec", paneId, cwd, briefPath, taskId, ct));
 
+    public async Task<LaunchSpec> GetResumeSessionLaunchSpecAsync(string sessionId, string paneId, CancellationToken ct = default)
+        => await InvokeTimedAsync<LaunchSpec>("GetResumeSessionLaunchSpec", () => _hub.InvokeAsync<LaunchSpec>("GetResumeSessionLaunchSpec", sessionId, paneId, ct));
+
     public async Task<LaunchSpec> GetMergeHelperLaunchSpecAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, string? model = null, CancellationToken ct = default)
         => await InvokeTimedAsync<LaunchSpec>("GetMergeHelperLaunchSpec", () => _hub.InvokeAsync<LaunchSpec>("GetMergeHelperLaunchSpec", taskIds, listId, handlerTaskId, model, ct));
 

src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs

@@ -5,6 +5,8 @@ using System.Linq;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using ClaudeDo.Data;
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
 using ClaudeDo.Ui.Localization;
 using ClaudeDo.Ui.Services;
 using ClaudeDo.Ui.ViewModels.MissionControl;
@@ -75,6 +77,12 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
     // fresh session is two clicks instead of navigating a folder picker.
     public ObservableCollection<SessionTargetViewModel> SessionTargets { get; } = new();
 
+    /// <summary>"Recent sessions" flyout rows: each chain's origin session, its handoffs right below it.</summary>
+    public ObservableCollection<RecentSessionViewModel> RecentSessions { get; } = new();
+
+    /// <summary>False shows the flyout's empty-state line.</summary>
+    public bool HasRecentSessions => RecentSessions.Count > 0;
+
     // View-layer seam: the folder picker needs a TopLevel, so the view owns it (see
     // MissionControlView.OnNewSessionClicked).
     public Action? BrowseForSessionRequested { get; set; }
@@ -215,6 +223,84 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         catch (Exception ex) { ErrorReported?.Invoke(Loc.T("missionControl.queueRefreshFailed", ex.Message)); }
     }
 
+    /// <summary>Rebuilds <see cref="RecentSessions"/> from the last 14 days (max 50 sessions); runs on
+    /// every flyout open.</summary>
+    internal async System.Threading.Tasks.Task RefreshRecentSessionsAsync()
+    {
+        try
+        {
+            await using var ctx = await _dbFactory.CreateDbContextAsync();
+            var sessions = await new MissionControlSessionRepository(ctx).ListRecentAsync(DateTime.UtcNow.AddDays(-14), 50);
+            var ids = sessions.Select(s => s.SessionId).ToList();
+            // A task's current session resumes through its task tile, so it stays deduped by TaskId.
+            var taskCurrent = (await ctx.Tasks.AsNoTracking()
+                .Where(t => t.InteractiveSessionId != null && ids.Contains(t.InteractiveSessionId))
+                .Select(t => t.InteractiveSessionId!)
+                .ToListAsync()).ToHashSet();
+
+            RecentSessions.Clear();
+            foreach (var (s, isHandoff) in NestHandoffs(sessions))
+            {
+                var time = DateTime.SpecifyKind(s.StartedAt, DateTimeKind.Utc).ToLocalTime().ToString("g");
+                var briefPath = s.BriefPath;
+                RecentSessions.Add(new RecentSessionViewModel
+                {
+                    Title = s.Title,
+                    Meta = isHandoff ? $"{Loc.T("missionControl.handoffSession")} · {time}" : $"{time} · {s.Cwd}",
+                    IsHandoff = isHandoff,
+                    ResumeCommand = new RelayCommand(() => ResumeSession(s, taskCurrent.Contains(s.SessionId))),
+                    ShowBriefCommand = briefPath is null ? null : new RelayCommand(() => ShowBrief(briefPath)),
+                });
+            }
+        }
+        catch (Exception ex) { ErrorReported?.Invoke(Loc.T("missionControl.queueRefreshFailed", ex.Message)); }
+        OnPropertyChanged(nameof(HasRecentSessions));
+    }
+
+    /// <summary>Orders newest-first sessions into chains: each origin session (no recorded predecessor
+    /// in the set) followed by every session handed off from it, directly or indirectly, oldest
+    /// first. Chains are ordered by their newest member.</summary>
+    internal static IEnumerable<(MissionControlSessionEntity Session, bool IsHandoff)> NestHandoffs(
+        IReadOnlyList<MissionControlSessionEntity> newestFirst)
+    {
+        var byId = newestFirst.ToDictionary(s => s.SessionId);
+        string RootOf(MissionControlSessionEntity s)
+        {
+            var seen = new HashSet<string>();
+            while (s.PredecessorSessionId is { } p && byId.TryGetValue(p, out var prev) && seen.Add(s.SessionId))
+                s = prev;
+            return s.SessionId;
+        }
+
+        return newestFirst
+            .GroupBy(RootOf)
+            .SelectMany(chain => chain
+                .OrderBy(s => s.SessionId != chain.Key)
+                .ThenBy(s => s.StartedAt)
+                .Select(s => (s, s.SessionId != chain.Key)));
+    }
+
+    // A task's current session reopens its task tile (deduped, same worktree guards); any other
+    // session gets a fresh ad-hoc tile resuming it in its recorded cwd.
+    private void ResumeSession(MissionControlSessionEntity session, bool isTaskCurrent)
+    {
+        if (session.TaskId is { } taskId && isTaskCurrent)
+        {
+            _ = OpenConPtySessionAsync(taskId);
+            return;
+        }
+        var paneId = Guid.NewGuid().ToString("n");
+        var sessionId = session.SessionId;
+        AddConPtyPane(new ConPtyPaneViewModel(null, session.Title,
+            () => DescribeAsync(() => _worker.GetResumeSessionLaunchSpecAsync(sessionId, paneId))) { IdentityKey = paneId });
+    }
+
+    private void ShowBrief(string briefPath)
+    {
+        var (ok, error) = ShellOpen.Path(briefPath);
+        if (!ok) ErrorReported?.Invoke(Loc.T("missionControl.briefOpenFailed", error ?? briefPath));
+    }
+
     // Drop-to-queue: a task dragged from the main app onto Mission Control gets queued. Goes
     // through the worker hub (TaskStateService.EnqueueAsync) rather than a raw EF write so the
     // manual/draft-child guards apply here too. The interactive-session check has to live here
@@ -674,6 +760,20 @@ public sealed class QueuedTaskViewModel
     public IRelayCommand? OpenSessionCommand { get; init; }
 }
 
+/// <summary>One row in the "Recent sessions" flyout.</summary>
+public sealed class RecentSessionViewModel
+{
+    public required string Title { get; init; }
+    /// <summary>Start time plus cwd (origin) or the handoff label (handoff).</summary>
+    public required string Meta { get; init; }
+    /// <summary>Indents the row under its chain's origin session.</summary>
+    public bool IsHandoff { get; init; }
+    public required IRelayCommand ResumeCommand { get; init; }
+    /// <summary>Opens the session's brief.md; null for a session that did not start from one.</summary>
+    public IRelayCommand? ShowBriefCommand { get; init; }
+    public bool HasBrief => ShowBriefCommand is not null;
+}
+
 /// <summary>One entry in the "new session" menu: a configured list's working dir, or browse.</summary>
 public sealed class SessionTargetViewModel
 {

src/ClaudeDo.Ui/Views/MissionControl/MissionControlView.axaml

@@ -48,6 +48,60 @@
               </MenuFlyout>
             </Button.Flyout>
           </Button>
+          <Button x:Name="RecentSessionsButton" Classes="icon-btn"
+                  ToolTip.Tip="{loc:Tr missionControl.recentSessions}">
+            <PathIcon Data="{StaticResource Icon.Clock}" Width="15" Height="15"/>
+            <Button.Flyout>
+              <Flyout Placement="BottomEdgeAlignedRight" ShowMode="Standard" Opening="OnRecentSessionsFlyoutOpening">
+                <StackPanel Width="380" Spacing="8" Margin="4">
+                  <TextBlock Classes="eyebrow"
+                             Text="{loc:Tr missionControl.recentSessions}"
+                             Foreground="{DynamicResource TextMuteBrush}"
+                             LetterSpacing="1.4" />
+                  <TextBlock Classes="meta"
+                             Text="{loc:Tr missionControl.recentSessionsEmpty}"
+                             IsVisible="{Binding !HasRecentSessions}"
+                             Foreground="{DynamicResource TextMuteBrush}" />
+                  <ScrollViewer MaxHeight="420">
+                    <ItemsControl x:Name="RecentSessionsList" ItemsSource="{Binding RecentSessions}">
+                      <ItemsControl.Styles>
+                        <Style Selector="Grid.handoff">
+                          <Setter Property="Margin" Value="{StaticResource NestedRowIndent}" />
+                        </Style>
+                      </ItemsControl.Styles>
+                      <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="vm:RecentSessionViewModel">
+                          <Grid ColumnDefinitions="*,Auto" Classes.handoff="{Binding IsHandoff}">
+                            <StackPanel Grid.Column="0" Spacing="2" Margin="0,4" VerticalAlignment="Center">
+                              <TextBlock Text="{Binding Title}"
+                                         TextTrimming="CharacterEllipsis"
+                                         ToolTip.Tip="{Binding Title}"
+                                         Foreground="{DynamicResource TextDimBrush}" />
+                              <TextBlock Classes="meta"
+                                         Text="{Binding Meta}"
+                                         TextTrimming="CharacterEllipsis"
+                                         ToolTip.Tip="{Binding Meta}"
+                                         Foreground="{DynamicResource TextMuteBrush}" />
+                            </StackPanel>
+                            <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="4"
+                                        VerticalAlignment="Center">
+                              <Button Classes="btn"
+                                      Content="{loc:Tr missionControl.showBrief}"
+                                      Command="{Binding ShowBriefCommand}"
+                                      IsVisible="{Binding HasBrief}" />
+                              <Button Classes="btn"
+                                      Content="{loc:Tr missionControl.resumeSession}"
+                                      Command="{Binding ResumeCommand}" />
+                            </StackPanel>
+                          </Grid>
+                        </DataTemplate>
+                      </ItemsControl.ItemTemplate>
+                    </ItemsControl>
+                  </ScrollViewer>
+                </StackPanel>
+              </Flyout>
+            </Button.Flyout>
+          </Button>
           <Button Classes="icon-btn"
                   Command="{Binding ToggleLayoutCommand}"
                   ToolTip.Tip="{Binding LayoutToggleLabel}">

src/ClaudeDo.Ui/Views/MissionControl/MissionControlView.axaml.cs

@@ -29,10 +29,14 @@ public partial class MissionControlView : UserControl
         InitializeComponent();
         DataContextChanged += OnDataContextChanged;
         QueueSplitter.DragCompleted += (_, _) => _queueWidth = BodyGrid.ColumnDefinitions[2].Width;
+        // Resume/Brief buttons don't close a plain Flyout on their own.
+        RecentSessionsList.AddHandler(Button.ClickEvent, (_, _) => RecentSessionsButton.Flyout?.Hide());
     }
 
     private void OnSessionFlyoutOpening(object? sender, EventArgs e) => _ = _vm?.RefreshSessionTargetsAsync();
 
+    private void OnRecentSessionsFlyoutOpening(object? sender, EventArgs e) => _ = _vm?.RefreshRecentSessionsAsync();
+
     // Ad-hoc ConPTY session: the view owns the folder picker, the VM only takes the chosen path.
     private async void BrowseForSessionAsync()
     {