chore(claude-do): refactor(ui): DetailsIslandViewModel (1431 Zeilen) in Sektio

Kontext: src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs ist mit 1431 Zeilen ein God-VM mit ~12 Concerns (Log-Streaming, Titel/Description-Editing, Subtasks, Child-Outcomes, Merge-Preview/-Targets, Diff, Agent-Settings-Overrides, Notes-Mode, Prep-Mode, Tabs, Session-Outcome/Roadblocks, Worktree-Info). Jedes neue Feature landet dort.

Änderungen — drei klar abgrenzbare Sektionen als ei

ClaudeDo-Task: 483e419f-1ec8-46ba-986b-8b90d6596b49

src/ClaudeDo.Ui/ViewModels/Islands/AgentSettingsSectionViewModel.cs

@@ -0,0 +1,196 @@
+using System.Collections.ObjectModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using ClaudeDo.Data.Models;
+using ClaudeDo.Ui.Helpers;
+using ClaudeDo.Ui.Localization;
+using ClaudeDo.Ui.Services;
+
+namespace ClaudeDo.Ui.ViewModels.Islands;
+
+public sealed partial class AgentSettingsSectionViewModel : ViewModelBase, IDisposable
+{
+    private readonly IWorkerClient _worker;
+    private readonly EventHandler _langChangedHandler;
+
+    internal string? TaskId { get; set; }
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(IsAgentSectionEnabled))]
+    private bool _isRunning;
+
+    public bool IsAgentSectionEnabled => !IsRunning;
+
+    [ObservableProperty] private string? _taskModelSelection;
+    [ObservableProperty] private string _taskSystemPrompt = "";
+    [ObservableProperty] private AgentInfo? _taskSelectedAgent;
+    [ObservableProperty] private decimal? _taskMaxTurns;
+    [ObservableProperty] private string _modelBadge = "";
+    [ObservableProperty] private string _modelInheritedHint = "";
+    [ObservableProperty] private string _turnsBadge = "";
+    [ObservableProperty] private string _turnsInheritedHint = "";
+    [ObservableProperty] private string _agentBadge = "";
+    [ObservableProperty] private string _effectiveSystemPromptHint = "";
+
+    private string _globalModel = ModelRegistry.DefaultAlias;
+    private int _globalMaxTurns = 100;
+    private string? _listModel;
+    private int? _listMaxTurns;
+    private string? _listAgentName;
+
+    private bool _suppressAgentSave;
+    private CancellationTokenSource? _agentSaveCts;
+
+    public int EffectiveMaxTurns =>
+        TaskMaxTurns is decimal t ? (int)t : (_listMaxTurns ?? _globalMaxTurns);
+
+    public ObservableCollection<string> TaskModelOptions { get; } = new(ModelRegistry.Aliases);
+    public ObservableCollection<AgentInfo> TaskAgentOptions { get; } = new();
+
+    public AgentSettingsSectionViewModel(IWorkerClient worker)
+    {
+        _worker = worker;
+        _langChangedHandler = (_, _) =>
+        {
+            RecomputeModelBadge();
+            RecomputeTurnsBadge();
+            RecomputeAgentBadge();
+        };
+        Loc.LanguageChanged += _langChangedHandler;
+    }
+
+    public void Dispose() => Loc.LanguageChanged -= _langChangedHandler;
+
+    partial void OnTaskModelSelectionChanged(string? value) { RecomputeModelBadge(); QueueAgentSave(); }
+
+    partial void OnTaskMaxTurnsChanged(decimal? value)
+    {
+        RecomputeTurnsBadge();
+        OnPropertyChanged(nameof(EffectiveMaxTurns));
+        QueueAgentSave();
+    }
+
+    partial void OnTaskSystemPromptChanged(string value) => QueueAgentSave();
+    partial void OnTaskSelectedAgentChanged(AgentInfo? value) { RecomputeAgentBadge(); QueueAgentSave(); }
+
+    private void RecomputeModelBadge()
+    {
+        var (value, source) = InheritanceResolver.Resolve(TaskModelSelection, _listModel, _globalModel);
+        ModelInheritedHint = value;
+        ModelBadge = BadgeFor(source, !string.IsNullOrWhiteSpace(TaskModelSelection));
+    }
+
+    private void RecomputeTurnsBadge()
+    {
+        var (value, source) = InheritanceResolver.Resolve(
+            TaskMaxTurns?.ToString(), _listMaxTurns?.ToString(), _globalMaxTurns.ToString());
+        TurnsInheritedHint = value;
+        TurnsBadge = BadgeFor(source, TaskMaxTurns is not null);
+    }
+
+    private void RecomputeAgentBadge()
+    {
+        var taskSet = TaskSelectedAgent is not null && !string.IsNullOrWhiteSpace(TaskSelectedAgent.Path);
+        var (_, source) = InheritanceResolver.Resolve(
+            taskSet ? TaskSelectedAgent!.Path : null, _listAgentName, null);
+        AgentBadge = BadgeFor(source, taskSet);
+    }
+
+    private static string BadgeFor(InheritSource source, bool taskSet) => taskSet
+        ? Loc.T("settings.inherit.overrideBadge")
+        : source == InheritSource.List
+            ? Loc.T("settings.inherit.inheritedFromList")
+            : Loc.T("settings.inherit.inheritedFromGlobal");
+
+    private void QueueAgentSave()
+    {
+        if (_suppressAgentSave || TaskId is null) return;
+        _agentSaveCts?.Cancel();
+        _agentSaveCts = new CancellationTokenSource();
+        _ = SaveAgentSettingsAsync(_agentSaveCts.Token);
+    }
+
+    private async System.Threading.Tasks.Task SaveAgentSettingsAsync(CancellationToken ct)
+    {
+        try
+        {
+            await System.Threading.Tasks.Task.Delay(300, ct);
+            if (TaskId is null) return;
+
+            var model = string.IsNullOrWhiteSpace(TaskModelSelection) ? null : TaskModelSelection;
+            var sp = string.IsNullOrWhiteSpace(TaskSystemPrompt) ? null : TaskSystemPrompt;
+            var ap = TaskSelectedAgent is null || string.IsNullOrWhiteSpace(TaskSelectedAgent.Path)
+                ? null : TaskSelectedAgent.Path;
+            var turns = TaskMaxTurns is decimal d ? (int?)d : null;
+
+            await _worker.UpdateTaskAgentSettingsAsync(
+                new UpdateTaskAgentSettingsDto(TaskId, model, sp, ap, turns));
+        }
+        catch (OperationCanceledException) { }
+        catch { }
+    }
+
+    internal async System.Threading.Tasks.Task LoadAsync(
+        ClaudeDo.Data.Models.TaskEntity entity, CancellationToken ct)
+    {
+        _suppressAgentSave = true;
+        try
+        {
+            TaskAgentOptions.Clear();
+            TaskAgentOptions.Add(new AgentInfo("(inherited)", "", ""));
+            var agents = await _worker.GetAgentsAsync();
+            foreach (var a in agents) TaskAgentOptions.Add(a);
+
+            TaskModelSelection = string.IsNullOrWhiteSpace(entity.Model) ? null : entity.Model!;
+            TaskMaxTurns = entity.MaxTurns is int tmt ? tmt : (decimal?)null;
+            TaskSystemPrompt = entity.SystemPrompt ?? "";
+            TaskSelectedAgent = string.IsNullOrWhiteSpace(entity.AgentPath)
+                ? TaskAgentOptions[0]
+                : (TaskAgentOptions.FirstOrDefault(a => a.Path == entity.AgentPath) ?? TaskAgentOptions[0]);
+
+            var listCfg = await _worker.GetListConfigAsync(entity.ListId);
+            var app = await _worker.GetAppSettingsAsync();
+            _globalModel = app?.DefaultModel ?? ModelRegistry.DefaultAlias;
+            _globalMaxTurns = app?.DefaultMaxTurns ?? 100;
+            _listModel = listCfg?.Model;
+            _listMaxTurns = listCfg?.MaxTurns;
+            _listAgentName = string.IsNullOrWhiteSpace(listCfg?.AgentPath)
+                ? null : System.IO.Path.GetFileName(listCfg!.AgentPath!);
+
+            EffectiveSystemPromptHint = string.IsNullOrWhiteSpace(listCfg?.SystemPrompt)
+                ? "" : listCfg!.SystemPrompt!;
+
+            RecomputeModelBadge();
+            RecomputeTurnsBadge();
+            RecomputeAgentBadge();
+            OnPropertyChanged(nameof(EffectiveMaxTurns));
+        }
+        finally
+        {
+            _suppressAgentSave = false;
+        }
+    }
+
+    internal void Clear()
+    {
+        _suppressAgentSave = true;
+        try
+        {
+            TaskModelSelection = null;
+            TaskMaxTurns = null;
+            TaskSystemPrompt = "";
+            TaskSelectedAgent = null;
+        }
+        finally
+        {
+            _suppressAgentSave = false;
+        }
+        EffectiveSystemPromptHint = "";
+        TaskId = null;
+    }
+
+    [RelayCommand] private void ResetTaskModel() => TaskModelSelection = null;
+    [RelayCommand] private void ResetTaskTurns() => TaskMaxTurns = null;
+    [RelayCommand] private void ResetTaskAgent() =>
+        TaskSelectedAgent = TaskAgentOptions.Count > 0 ? TaskAgentOptions[0] : null;
+}

src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs

@@ -53,6 +53,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     private readonly IServiceProvider _services;
     private readonly INotesApi _notesApi;
 
+    // ── Section view models ───────────────────────────────────────────────────
+    public AgentSettingsSectionViewModel AgentSettings { get; }
+    public MergeSectionViewModel Merge { get; }
+    public PrepPanelViewModel Prep { get; }
+
     // Captured handler delegates for disposal
     private readonly EventHandler _langChangedHandler;
     private readonly System.ComponentModel.PropertyChangedEventHandler _workerPropertyChangedHandler;
@@ -63,8 +68,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     [ObservableProperty] private bool _isNotesMode;
     [ObservableProperty] private bool _isPrepMode;
-    [ObservableProperty] private bool _isPrepRunning;
+
-    public ObservableCollection<LogLineViewModel> PrepLog { get; } = new();
     public bool IsTaskDetailVisible => !IsNotesMode && !IsPrepMode;
 
     partial void OnIsNotesModeChanged(bool value) => OnPropertyChanged(nameof(IsTaskDetailVisible));
@@ -77,7 +81,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     [NotifyCanExecuteChangedFor(nameof(EnqueueCommand))]
     [NotifyCanExecuteChangedFor(nameof(DequeueCommand))]
     [NotifyCanExecuteChangedFor(nameof(ResetAndRetryCommand))]
-    [NotifyCanExecuteChangedFor(nameof(ReviewCombinedDiffCommand))]
     [NotifyPropertyChangedFor(nameof(TaskIdBadge))]
     private TaskRowViewModel? _task;
 
@@ -112,9 +115,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     [RelayCommand]
     private void ToggleDescriptionExpanded() => IsDescriptionExpanded = !IsDescriptionExpanded;
 
-    // ── Description / Steps card (redesign) ─────────────────────────────
-    // Description is always the card body; steps live in an expandable summary
-    // strip below it so step presence is visible without switching views.
     [ObservableProperty] private bool _isStepsExpanded;
 
     [RelayCommand]
@@ -135,14 +135,10 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         OnPropertyChanged(nameof(ComposedPreview));
     }
 
-    // The exact text handed to Claude: title + description + open steps only.
     public string ComposedPreview =>
         ClaudeDo.Data.TaskPromptComposer.Compose(
             EditableTitle, EditableDescription, Subtasks.Select(s => (s.Title, s.Done)));
 
-    // ── Work console (redesign) ────────────────────────────────────────
-    // Two tabs: Output (live log) and Session (review + merge/worktree +
-    // outcomes, each section gated on the relevant state).
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(IsOutputTab))]
     [NotifyPropertyChangedFor(nameof(IsGitTab))]
@@ -156,39 +152,25 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     [RelayCommand]
     private void SelectTab(string? tab) => SelectedTab = tab ?? "output";
 
-    // Merge/worktree controls only matter once there's a worktree to manage
-    // (standalone task), or a planning parent / improvement parent with children.
-    public bool ShowMergeSection =>
-        WorktreePath != null || Task?.IsPlanningParent == true || HasChildOutcomes;
-
     private void NotifySessionSections()
     {
         OnPropertyChanged(nameof(HasChildOutcomes));
-        OnPropertyChanged(nameof(ShowMergeSection));
+        Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
         NotifyAttention();
 
-        // The Session tab is only visible when it has outcomes; if it just
-        // emptied while selected, fall back to Output so the body isn't blank.
         if (!HasChildOutcomes && SelectedTab == "session")
             SelectedTab = "output";
     }
 
-    public string TurnsText   => $"{Turns}/{EffectiveMaxTurns}";
+    public string TurnsText   => $"{Turns}/{AgentSettings.EffectiveMaxTurns}";
     public string DiffAddText => $"+{DiffAdditions}";
     public string DiffDelText => $"-{DiffDeletions}";
 
-    // Resolved turn budget: per-task override → list default → global default.
-    public int EffectiveMaxTurns =>
-        TaskMaxTurns is decimal t ? (int)t : (_listMaxTurns ?? _globalMaxTurns);
-
     public bool ShowRoadblock => IsFailed || IsCancelled;
     public string RoadblockMessage =>
         IsFailed ? "The session ended with an error." :
         IsCancelled ? "The session was cancelled." : "";
 
-    // The session's outcome summary — the task's Result minus any roadblock
-    // section (those get their own card), falling back to the run's
-    // ErrorMarkdown for hard failures. Shown once a run has finished.
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowSessionOutcome))]
     private string? _sessionOutcome;
@@ -197,8 +179,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         !string.IsNullOrWhiteSpace(SessionOutcome)
         && (IsWaitingForReview || IsDone || IsFailed || IsCancelled);
 
-    // The roadblocks the agent emitted (CLAUDEDO_BLOCKED), parsed out of the
-    // run result so they can surface as a distinct colored card.
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowRoadblockCard))]
     private string? _roadblocks;
@@ -207,8 +187,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         !string.IsNullOrWhiteSpace(Roadblocks)
         && (IsWaitingForReview || IsDone || IsFailed || IsCancelled);
 
-    // Worker writes roadblocks into the result under this header
-    // (TaskRunner.ComposeReviewResult). Split it back out for display.
     private const string RoadblockMarker = "Roadblocks reported during the run:";
 
     private void ApplyOutcome(string? result, string? errorFallback)
@@ -235,7 +213,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     public string SessionLabel => "claude-session";
 
-    // Short task-id badge, e.g. "#T1A"
     public string TaskIdBadge => Task != null ? $"#T{Task.Id[..Math.Min(3, Task.Id.Length)].ToUpperInvariant()}" : "";
 
     [ObservableProperty]
@@ -254,9 +231,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     public bool IsFailed             => AgentState == "failed";
     public bool IsCancelled          => AgentState == "cancelled";
 
-    // Recovery actions: Continue (resume session) for Failed/Cancelled.
     public bool ShowContinue => IsFailed || IsCancelled;
-    // Reset & retry available from any terminal state.
     public bool ShowResetAndRetry => IsFailed || IsCancelled || IsDone;
 
     [ObservableProperty]
@@ -276,89 +251,20 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         OnPropertyChanged(nameof(IsCancelled));
         OnPropertyChanged(nameof(ShowContinue));
         OnPropertyChanged(nameof(ShowResetAndRetry));
-        OnPropertyChanged(nameof(IsAgentSectionEnabled));
         OnPropertyChanged(nameof(ShowRoadblock));
         OnPropertyChanged(nameof(RoadblockMessage));
         OnPropertyChanged(nameof(ShowSessionOutcome));
         OnPropertyChanged(nameof(ShowRoadblockCard));
+        AgentSettings.IsRunning = IsRunning;
         NotifySessionSections();
     }
+
     [ObservableProperty] private string? _model;
 
-    // Agent settings overrides
-    [ObservableProperty] private string? _taskModelSelection;     // null = inherit
-    [ObservableProperty] private string _taskSystemPrompt = "";
-    [ObservableProperty] private AgentInfo? _taskSelectedAgent;
-    [ObservableProperty] private decimal? _taskMaxTurns;          // null = inherit
-    [ObservableProperty] private string _modelBadge = "";
-    [ObservableProperty] private string _modelInheritedHint = "";
-    [ObservableProperty] private string _turnsBadge = "";
-    [ObservableProperty] private string _turnsInheritedHint = "";
-    [ObservableProperty] private string _agentBadge = "";
-    [ObservableProperty] private string _effectiveSystemPromptHint = "";
-
-    private string _globalModel = ModelRegistry.DefaultAlias;
-    private int _globalMaxTurns = 100;
-    private string? _listModel;
-    private int? _listMaxTurns;
-    private string? _listAgentName;
-
-    partial void OnTaskModelSelectionChanged(string? value) { RecomputeModelBadge(); QueueAgentSave(); }
-    partial void OnTaskMaxTurnsChanged(decimal? value)
-    {
-        RecomputeTurnsBadge();
-        OnPropertyChanged(nameof(EffectiveMaxTurns));
-        OnPropertyChanged(nameof(TurnsText));
-        QueueAgentSave();
-    }
-
-    private void RecomputeModelBadge()
-    {
-        var (value, source) = InheritanceResolver.Resolve(TaskModelSelection, _listModel, _globalModel);
-        ModelInheritedHint = value;
-        ModelBadge = BadgeFor(source, !string.IsNullOrWhiteSpace(TaskModelSelection));
-    }
-
-    private void RecomputeTurnsBadge()
-    {
-        var (value, source) = InheritanceResolver.Resolve(
-            TaskMaxTurns?.ToString(), _listMaxTurns?.ToString(), _globalMaxTurns.ToString());
-        TurnsInheritedHint = value;
-        TurnsBadge = BadgeFor(source, TaskMaxTurns is not null);
-    }
-
-    private void RecomputeAgentBadge()
-    {
-        var taskSet = TaskSelectedAgent is not null && !string.IsNullOrWhiteSpace(TaskSelectedAgent.Path);
-        var (_, source) = InheritanceResolver.Resolve(
-            taskSet ? TaskSelectedAgent!.Path : null, _listAgentName, null);
-        AgentBadge = BadgeFor(source, taskSet);
-    }
-
-    private static string BadgeFor(InheritSource source, bool taskSet) => taskSet
-        ? Loc.T("settings.inherit.overrideBadge")
-        : source == InheritSource.List
-            ? Loc.T("settings.inherit.inheritedFromList")
-            : Loc.T("settings.inherit.inheritedFromGlobal");
-
-    public System.Collections.ObjectModel.ObservableCollection<string> TaskModelOptions { get; } = new(ModelRegistry.Aliases);
-
-    public System.Collections.ObjectModel.ObservableCollection<AgentInfo> TaskAgentOptions { get; } = new();
-
-    private bool _suppressAgentSave;
-    private CancellationTokenSource? _agentSaveCts;
-
-    private bool _suppressDescSave;
-    private CancellationTokenSource? _descSaveCts;
-
-    public bool IsAgentSectionEnabled => !IsRunning;
-
     [ObservableProperty] private string? _worktreePath;
     [ObservableProperty] private string? _worktreeBaseCommit;
     [ObservableProperty] private string? _worktreeHeadCommit;
     [ObservableProperty] private string? _worktreeStateLabel;
-    // Repo working dir of the selected task's list — used to diff a merged task's
-    // commit range after its worktree directory is gone.
     private string? _listWorkingDir;
     [ObservableProperty] private string? _branchLine;
     [ObservableProperty] private int _turns;
@@ -368,14 +274,13 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     [ObservableProperty] private int _commitsOnBranch;
 
     public string TokensFormatted => Tokens >= 1000 ? $"{Tokens / 1000.0:F1}k" : Tokens.ToString();
-    public string ElapsedFormatted => "";  // placeholder — no start-time stored yet
+    public string ElapsedFormatted => "";
 
     partial void OnTokensChanged(int value)   => OnPropertyChanged(nameof(TokensFormatted));
     partial void OnTurnsChanged(int value)    => OnPropertyChanged(nameof(TurnsText));
     partial void OnDiffAdditionsChanged(int value) { OnPropertyChanged(nameof(DiffMeterRatio)); OnPropertyChanged(nameof(DiffAddText)); }
     partial void OnDiffDeletionsChanged(int value) { OnPropertyChanged(nameof(DiffMeterRatio)); OnPropertyChanged(nameof(DiffDelText)); }
 
-    // 0.0–1.0 additions share for the diff meter
     public double DiffMeterRatio
     {
         get
@@ -387,16 +292,9 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     public ObservableCollection<LogLineViewModel> Log { get; } = new();
     public ObservableCollection<SubtaskRowViewModel> Subtasks { get; } = new();
-
-    // Agent-suggested improvement children of a non-planning parent, surfaced on its
-    // review card with each child's outcome and rolled-up roadblock count.
     public ObservableCollection<ChildOutcomeRowViewModel> ChildOutcomes { get; } = new();
     public bool HasChildOutcomes => ChildOutcomes.Count > 0;
 
-    // Children that need the user's attention before the parent can be approved:
-    // failed, cancelled, still awaiting their own review, or that reported roadblocks.
-    // The parent deliberately stays in WaitingForChildren until these are resolved;
-    // this surfaces a flag so the roadblock is visible on the parent.
     public int ChildrenNeedingAttention => ChildOutcomes.Count(c =>
         c.Status == ClaudeDo.Data.Models.TaskStatus.Failed
         || c.Status == ClaudeDo.Data.Models.TaskStatus.Cancelled
@@ -416,59 +314,37 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
     [ObservableProperty] private string _newSubtaskTitle = "";
 
-    // Planning merge controls
-    [ObservableProperty] private ObservableCollection<string> _mergeTargetBranches = new();
-    [ObservableProperty] private string? _selectedMergeTarget;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
-    private string _mergePreviewText = "";
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
-    private bool _mergeIsClean;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
-    private bool _mergeIsConflict;
-
-    public bool ShowMergePreviewMuted =>
-        !MergeIsClean && !MergeIsConflict && !string.IsNullOrEmpty(MergePreviewText);
-
     // Claude CLI stream-json parser + buffer for partial text deltas
     private readonly StreamLineFormatter _formatter = new();
     private readonly StringBuilder _claudeBuf = new();
-    private readonly StringBuilder _prepClaudeBuf = new();
 
-    // The task ID we are currently subscribed to for live log messages
     private string? _subscribedTaskId;
-
     private CancellationTokenSource? _loadCts;
 
+    private bool _suppressDescSave;
+    private CancellationTokenSource? _descSaveCts;
+
     // Set by shell so CloseDetailCommand can clear SelectedTask
     public Action? CloseDetail { get; set; }
 
     // Set by shell so DeleteTaskCommand can remove from list
     public Func<TaskRowViewModel, System.Threading.Tasks.Task>? DeleteFromList { get; set; }
 
-    // Set by the view so OpenDiffCommand can show the modal as a dialog
-    public Func<DiffModalViewModel, System.Threading.Tasks.Task>? ShowDiffModal { get; set; }
-
-    // Set by the view so OpenDiff can pass through merge requests from the diff modal
-    public Func<MergeModalViewModel, System.Threading.Tasks.Task>? ShowMergeModal { get; set; }
-
     // Set by the view so DeleteTaskCommand can prompt yes/no before deleting
     public Func<string, System.Threading.Tasks.Task<bool>>? ConfirmAsync { get; set; }
 
-    // Set by the view so ReviewCombinedDiffCommand can show the planning diff modal
-    public Func<ViewModels.Planning.PlanningDiffViewModel, System.Threading.Tasks.Task>? ShowPlanningDiffModal { get; set; }
-
     // Set by the view so DeleteTaskCommand can show an error message
     public Func<string, System.Threading.Tasks.Task>? ShowErrorAsync { get; set; }
 
-    // Invoked when a single-task merge/approve hits a conflict. Wired by the
+    // ── Review ──────────────────────────────────────────────────────────────
-    // integrator to Layer C's conflict resolver. Args: (taskId, targetBranch).
+    [ObservableProperty] private string _reviewFeedback = "";
-    public Func<string, string, System.Threading.Tasks.Task>? RequestConflictResolution { get; set; }
+
+    // Kept for backwards-compat surface — delegates to Merge.RequestConflictResolution
+    public Func<string, string, System.Threading.Tasks.Task>? RequestConflictResolution
+    {
+        get => Merge.RequestConflictResolution;
+        set => Merge.RequestConflictResolution = value;
+    }
 
     private static string StatusToStateKey(ClaudeDo.Data.Models.TaskStatus status) => status switch
     {
@@ -507,8 +383,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         catch { }
     }
 
-    // Reload the session outcome (task Result incl. roadblocks, or the run's
-    // error) so it appears as soon as a run finishes.
     private async System.Threading.Tasks.Task RefreshOutcomeAsync(string taskId)
     {
         try
@@ -522,30 +396,36 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         catch { }
     }
 
-    public DetailsIslandViewModel(IDbContextFactory<ClaudeDoDbContext> dbFactory, IWorkerClient worker, IServiceProvider services, INotesApi notesApi)
+    public DetailsIslandViewModel(
+        IDbContextFactory<ClaudeDoDbContext> dbFactory,
+        IWorkerClient worker,
+        IServiceProvider services,
+        INotesApi notesApi)
     {
         _dbFactory = dbFactory;
         _worker = worker;
         _services = services;
         _notesApi = notesApi;
+
+        AgentSettings = new AgentSettingsSectionViewModel(worker);
+        Merge = new MergeSectionViewModel(worker, services);
+        Prep = new PrepPanelViewModel(worker);
+
         Notes = new NotesEditorViewModel(_notesApi);
         Subtasks.CollectionChanged += (_, _) => NotifyStepsChanged();
-        _langChangedHandler = (_, _) =>
+        Subtasks.CollectionChanged += (_, _) => Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
+
+        AgentSettings.PropertyChanged += (_, e) =>
         {
-            OnPropertyChanged(nameof(AgentStatusLabel));
+            if (e.PropertyName == nameof(AgentSettingsSectionViewModel.EffectiveMaxTurns))
-            RecomputeModelBadge();
+                OnPropertyChanged(nameof(TurnsText));
-            RecomputeTurnsBadge();
-            RecomputeAgentBadge();
         };
+
+        _langChangedHandler = (_, _) => OnPropertyChanged(nameof(AgentStatusLabel));
         Loc.LanguageChanged += _langChangedHandler;
 
-        // Subscribe once; filter by current task id inside the handler
         _worker.TaskMessageEvent += OnTaskMessage;
-        _worker.PrepStartedEvent  += OnPrepStarted;
-        _worker.PrepLineEvent     += OnPrepLine;
-        _worker.PrepFinishedEvent += OnPrepFinished;
 
-        // Re-evaluate CanExecute when worker connection flips.
         _workerPropertyChangedHandler = (_, e) =>
         {
             if (e.PropertyName == nameof(IWorkerClient.IsConnected))
@@ -558,7 +438,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         };
         _worker.PropertyChanged += _workerPropertyChangedHandler;
 
-        // If the task row's live status changes (e.g. TaskStarted/Finished), mirror it.
         _workerTaskStartedHandler = (slot, taskId, startedAt) =>
         {
             if (Task?.Id == taskId) AgentState = "running";
@@ -576,7 +455,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 Text = $"── {status.ToUpperInvariant()} · {finishedAt.ToLocalTime():HH:mm:ss} ──",
             });
             AgentState = FinishedStatusToStateKey(status);
-            // Re-query to pick up worktree created during the run.
             _ = RefreshWorktreeAsync(taskId);
             _ = RefreshChildOutcomeAsync(taskId);
             _ = RefreshOutcomeAsync(taskId);
@@ -599,18 +477,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         };
         _worker.TaskUpdatedEvent += _workerTaskUpdatedHandler;
 
-        Subtasks.CollectionChanged += (_, _) =>
-        {
-            ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
-        };
-
         ChildOutcomes.CollectionChanged += (_, _) =>
         {
-            ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
+            Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
             NotifySessionSections();
         };
-
-        PrepLog.CollectionChanged += (_, _) => OnPropertyChanged(nameof(ShowPrepEmptyState));
     }
 
     public void Dispose()
@@ -622,25 +493,21 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         _worker.WorktreeUpdatedEvent -= _workerWorktreeUpdatedHandler;
         _worker.TaskUpdatedEvent -= _workerTaskUpdatedHandler;
         _worker.TaskMessageEvent -= OnTaskMessage;
-        _worker.PrepStartedEvent -= OnPrepStarted;
+        AgentSettings.Dispose();
-        _worker.PrepLineEvent -= OnPrepLine;
+        Prep.Dispose();
-        _worker.PrepFinishedEvent -= OnPrepFinished;
     }
 
     private void OnTaskMessage(string taskId, string line)
     {
         if (taskId != _subscribedTaskId) return;
 
-        // `[stdout] ...json...` lines are Claude CLI stream-json; parse through the
-        // formatter so the user sees human text, not raw JSON.
         if (line.StartsWith("[stdout]", StringComparison.OrdinalIgnoreCase))
         {
             var body = line["[stdout]".Length..].TrimStart();
-            AppendStdoutLine(Log, body);
+            AppendStdoutLine(body);
             return;
         }
 
-        // Non-stdout tagged lines: flush any buffered text then classify by prefix.
         FlushClaudeBuffer();
 
         var kind = line.StartsWith("[sys]", StringComparison.OrdinalIgnoreCase)    ? LogKind.Sys
@@ -652,52 +519,21 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         Log.Add(new LogLineViewModel { Kind = kind, Text = line });
     }
 
-    private void AppendStdoutLine(ObservableCollection<LogLineViewModel> target, string line)
+    private void AppendStdoutLine(string line)
     {
         var formatted = _formatter.FormatLine(line);
         if (formatted is null) return;
-        var buf = ReferenceEquals(target, Log) ? _claudeBuf : _prepClaudeBuf;
+        _claudeBuf.Append(formatted);
-        AppendClaudeText(formatted, target, buf);
-    }
-
-    [RelayCommand]
-    private async Task PlanDayAsync()
-    {
-        if (_worker is null) return;
-        try { await _worker.RunDailyPrepNowAsync(); }
-        catch { /* worker offline; PrepStarted/PrepLine will reconcile */ }
-    }
-
-    public bool ShowPrepEmptyState => !IsPrepRunning && PrepLog.Count == 0;
-
-    partial void OnIsPrepRunningChanged(bool value) => OnPropertyChanged(nameof(ShowPrepEmptyState));
-
-    private void OnPrepStarted()
-    {
-        PrepLog.Clear();
-        IsPrepRunning = true;
-    }
-
-    private void OnPrepLine(string line) => AppendStdoutLine(PrepLog, line);
-
-    private void OnPrepFinished(bool success) => IsPrepRunning = false;
-
-    private void AppendClaudeText(string chunk) => AppendClaudeText(chunk, Log, _claudeBuf);
-
-    private static void AppendClaudeText(string chunk, ObservableCollection<LogLineViewModel> target, StringBuilder buf)
-    {
-        buf.Append(chunk);
-        // Emit a log entry for every completed line; keep the trailing remainder buffered.
         while (true)
         {
-            var text = buf.ToString();
+            var text = _claudeBuf.ToString();
             var nl = text.IndexOf('\n');
             if (nl < 0) break;
             var piece = text[..nl].TrimEnd('\r');
             if (!string.IsNullOrWhiteSpace(piece))
-                target.Add(new LogLineViewModel { Kind = LogKind.Claude, Text = piece });
+                Log.Add(new LogLineViewModel { Kind = LogKind.Claude, Text = piece });
-            buf.Clear();
+            _claudeBuf.Clear();
-            buf.Append(text[(nl + 1)..]);
+            _claudeBuf.Append(text[(nl + 1)..]);
         }
     }
 
@@ -710,9 +546,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             Log.Add(new LogLineViewModel { Kind = LogKind.Claude, Text = piece });
     }
 
-    partial void OnTaskSystemPromptChanged(string value) => QueueAgentSave();
-    partial void OnTaskSelectedAgentChanged(AgentInfo? value) { RecomputeAgentBadge(); QueueAgentSave(); }
-
     partial void OnEditableDescriptionChanged(string value)
     {
         if (_suppressDescSave || Task is null) return;
@@ -738,76 +571,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         catch { }
     }
 
-    private void QueueAgentSave()
-    {
-        if (_suppressAgentSave || Task is null) return;
-        _agentSaveCts?.Cancel();
-        _agentSaveCts = new CancellationTokenSource();
-        var ct = _agentSaveCts.Token;
-        _ = SaveAgentSettingsAsync(ct);
-    }
-
-    private async System.Threading.Tasks.Task SaveAgentSettingsAsync(CancellationToken ct)
-    {
-        try
-        {
-            await System.Threading.Tasks.Task.Delay(300, ct);
-            if (Task is null) return;
-
-            var model = string.IsNullOrWhiteSpace(TaskModelSelection) ? null : TaskModelSelection;
-            var sp = string.IsNullOrWhiteSpace(TaskSystemPrompt) ? null : TaskSystemPrompt;
-            var ap = TaskSelectedAgent is null || string.IsNullOrWhiteSpace(TaskSelectedAgent.Path)
-                ? null : TaskSelectedAgent.Path;
-            var turns = TaskMaxTurns is decimal d ? (int?)d : null;
-
-            await _worker.UpdateTaskAgentSettingsAsync(
-                new ClaudeDo.Ui.Services.UpdateTaskAgentSettingsDto(Task.Id, model, sp, ap, turns));
-        }
-        catch (OperationCanceledException) { }
-        catch { }
-    }
-
-    private async System.Threading.Tasks.Task LoadAgentSettingsAsync(
-        ClaudeDo.Data.Models.TaskEntity entity, CancellationToken ct)
-    {
-        _suppressAgentSave = true;
-        try
-        {
-            TaskAgentOptions.Clear();
-            TaskAgentOptions.Add(new AgentInfo("(inherited)", "", ""));
-            var agents = await _worker.GetAgentsAsync();
-            foreach (var a in agents) TaskAgentOptions.Add(a);
-
-            TaskModelSelection = string.IsNullOrWhiteSpace(entity.Model) ? null : entity.Model!;
-            TaskMaxTurns = entity.MaxTurns is int tmt ? tmt : (decimal?)null;
-            TaskSystemPrompt = entity.SystemPrompt ?? "";
-            TaskSelectedAgent = string.IsNullOrWhiteSpace(entity.AgentPath)
-                ? TaskAgentOptions[0]
-                : (TaskAgentOptions.FirstOrDefault(a => a.Path == entity.AgentPath) ?? TaskAgentOptions[0]);
-
-            var listCfg = await _worker.GetListConfigAsync(entity.ListId);
-            var app = await _worker.GetAppSettingsAsync();
-            _globalModel = app?.DefaultModel ?? ModelRegistry.DefaultAlias;
-            _globalMaxTurns = app?.DefaultMaxTurns ?? 100;
-            _listModel = listCfg?.Model;
-            _listMaxTurns = listCfg?.MaxTurns;
-            _listAgentName = string.IsNullOrWhiteSpace(listCfg?.AgentPath)
-                ? null : System.IO.Path.GetFileName(listCfg!.AgentPath!);
-
-            EffectiveSystemPromptHint = string.IsNullOrWhiteSpace(listCfg?.SystemPrompt) ? "" : listCfg!.SystemPrompt!;
-
-            RecomputeModelBadge();
-            RecomputeTurnsBadge();
-            RecomputeAgentBadge();
-            OnPropertyChanged(nameof(EffectiveMaxTurns));
-            OnPropertyChanged(nameof(TurnsText));
-        }
-        finally
-        {
-            _suppressAgentSave = false;
-        }
-    }
-
     public void ShowNotes()
     {
         Bind(null);
@@ -821,21 +584,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         Bind(null);
         IsNotesMode = false;
         IsPrepMode = true;
-        _ = LoadLastPrepLogIfEmptyAsync();
+        _ = Prep.LoadLastPrepLogIfEmptyAsync();
-    }
-
-    public async Task LoadLastPrepLogIfEmptyAsync()
-    {
-        if (_worker is null || IsPrepRunning || PrepLog.Count > 0) return;
-        string text;
-        try { text = await _worker.GetLastPrepLogAsync(); }
-        catch { return; }
-        if (IsPrepRunning || PrepLog.Count > 0) return;
-        foreach (var line in text.Split('\n'))
-        {
-            var trimmed = line.TrimEnd('\r');
-            if (trimmed.Length > 0) AppendStdoutLine(PrepLog, trimmed);
-        }
     }
 
     public void Bind(TaskRowViewModel? row)
@@ -853,11 +602,10 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         Subtasks.Clear();
         ChildOutcomes.Clear();
         OnPropertyChanged(nameof(HasChildOutcomes));
-        MergeTargetBranches.Clear();
-        SelectedMergeTarget = null;
         SessionOutcome = null;
         Roadblocks = null;
         _claudeBuf.Clear();
+        Merge.Clear();
 
         if (row == null)
         {
@@ -874,19 +622,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             DiffDeletions = 0;
             AgentState = "idle";
             LatestRunSessionId = null;
-            _suppressAgentSave = true;
+            AgentSettings.Clear();
-            try
-            {
-                TaskModelSelection = null;
-                TaskMaxTurns = null;
-                TaskSystemPrompt = "";
-                TaskSelectedAgent = null;
-            }
-            finally
-            {
-                _suppressAgentSave = false;
-            }
-            EffectiveSystemPromptHint = "";
             return;
         }
 
@@ -900,7 +636,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             await using var ctx = await _dbFactory.CreateDbContextAsync(ct);
             var subtaskRepo = new SubtaskRepository(ctx);
 
-            // Own query with Include so WorktreePath/BranchLine are populated.
             var entity = await ctx.Tasks
                 .AsNoTracking()
                 .Include(t => t.Worktree)
@@ -919,12 +654,18 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             WorktreeBaseCommit = entity.Worktree?.BaseCommit;
             WorktreeHeadCommit = entity.Worktree?.HeadCommit;
             WorktreeStateLabel = entity.Worktree?.State.ToString();
-            BranchLine = entity.Worktree is { } w ? $"{w.BranchName} \u2190 main" : null;
+            BranchLine = entity.Worktree is { } w ? $"{w.BranchName} ← main" : null;
             var (add, del) = ParseDiffStat(entity.Worktree?.DiffStat);
             DiffAdditions = add;
             DiffDeletions = del;
             AgentState = StatusToStateKey(entity.Status);
-            await LoadAgentSettingsAsync(entity, ct);
+
+            Merge.SyncTaskContext(row.Id, row.Title, row.IsPlanningParent);
+            Merge.SyncWorktree(WorktreePath, WorktreeBaseCommit, WorktreeHeadCommit,
+                WorktreeStateLabel, _listWorkingDir);
+
+            AgentSettings.TaskId = row.Id;
+            await AgentSettings.LoadAsync(entity, ct);
             ct.ThrowIfCancellationRequested();
 
             var runRepo = new TaskRunRepository(ctx);
@@ -933,10 +674,8 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             LatestRunSessionId = latestRun?.SessionId;
             ApplyOutcome(entity.Result, latestRun?.ErrorMarkdown);
 
-            // Subscribe only after DB load confirms the task exists
             _subscribedTaskId = row.Id;
 
-            // Replay the latest run's persisted log so output is visible across app restarts.
             await ReplayLogFileAsync(entity.LogPath, ct);
 
             var subs = await subtaskRepo.GetByTaskIdAsync(row.Id);
@@ -946,31 +685,25 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
 
             if (entity.PlanningPhase != ClaudeDo.Data.Models.PlanningPhase.None)
                 await LoadPlanningChildrenAsync(row.Id, ct);
-            // Surface every parent's children — planning or improvement — in the
-            // Session tab with their live status + roadblock count. This is what
-            // makes the Session tab appear for planning parents and lets a child's
-            // roadblock register on the parent.
             await LoadChildOutcomesAsync(row.Id, ct);
 
             if (entity.Worktree != null
                 && entity.PlanningPhase == ClaudeDo.Data.Models.PlanningPhase.None
-                && MergeTargetBranches.Count == 0)
+                && Merge.MergeTargetBranches.Count == 0)
             {
                 var targets = await _worker.GetMergeTargetsAsync(row.Id);
                 if (targets != null)
                 {
-                    MergeTargetBranches.Clear();
+                    Merge.MergeTargetBranches.Clear();
-                    foreach (var b in targets.LocalBranches) MergeTargetBranches.Add(b);
+                    foreach (var b in targets.LocalBranches) Merge.MergeTargetBranches.Add(b);
-                    SelectedMergeTarget = targets.DefaultBranch; // triggers OnSelectedMergeTargetChanged → preview
+                    Merge.SelectedMergeTarget = targets.DefaultBranch;
                 }
             }
-            await RefreshMergePreviewAsync();
+            await Merge.RefreshMergePreviewAsync();
         }
         catch (OperationCanceledException) { }
     }
 
-    // Improvement parents (non-planning) surface their children's outcomes + roadblocks
-    // on the review card, and reuse the planning merge controls to fold the tree in.
     private async System.Threading.Tasks.Task LoadChildOutcomesAsync(string parentTaskId, CancellationToken ct)
     {
         try
@@ -997,7 +730,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 });
             OnPropertyChanged(nameof(HasChildOutcomes));
 
-            if (MergeTargetBranches.Count == 0)
+            if (Merge.MergeTargetBranches.Count == 0)
             {
                 var childWithWorktree = children.FirstOrDefault(c => c.Worktree != null);
                 if (childWithWorktree != null)
@@ -1005,14 +738,13 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                     var targets = await _worker.GetMergeTargetsAsync(childWithWorktree.Id);
                     if (targets != null)
                     {
-                        MergeTargetBranches.Clear();
+                        Merge.MergeTargetBranches.Clear();
                         foreach (var b in targets.LocalBranches)
-                            MergeTargetBranches.Add(b);
+                            Merge.MergeTargetBranches.Add(b);
-                        SelectedMergeTarget = targets.DefaultBranch;
+                        Merge.SelectedMergeTarget = targets.DefaultBranch;
                     }
                 }
             }
-
         }
         catch (OperationCanceledException) { }
         catch { /* best-effort */ }
@@ -1047,9 +779,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             {
                 ct.ThrowIfCancellationRequested();
                 if (_subscribedTaskId is null) return;
-                // Worker writes raw Claude CLI stdout to disk (no prefix) but broadcasts
-                // it with a "[stdout] " prefix. Match the live-stream format so the same
-                // stream-json parser handles both.
                 var line = all[i];
                 var normalized = line.StartsWith("[", StringComparison.Ordinal) ? line : "[stdout] " + line;
                 OnTaskMessage(_subscribedTaskId, normalized);
@@ -1093,7 +822,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 }
             }
 
-            if (MergeTargetBranches.Count == 0)
+            if (Merge.MergeTargetBranches.Count == 0)
             {
                 var childWithWorktree = children.FirstOrDefault(c => c.Worktree != null);
                 if (childWithWorktree != null)
@@ -1101,14 +830,13 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                     var targets = await _worker.GetMergeTargetsAsync(childWithWorktree.Id);
                     if (targets != null)
                     {
-                        MergeTargetBranches.Clear();
+                        Merge.MergeTargetBranches.Clear();
                         foreach (var b in targets.LocalBranches)
-                            MergeTargetBranches.Add(b);
+                            Merge.MergeTargetBranches.Add(b);
-                        SelectedMergeTarget = targets.DefaultBranch;
+                        Merge.SelectedMergeTarget = targets.DefaultBranch;
                     }
                 }
             }
-
         }
         catch (OperationCanceledException) { }
         catch { /* best-effort */ }
@@ -1132,13 +860,10 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
                 existing.Status = child.Status;
                 existing.WorktreeState = child.Worktree?.State ?? ClaudeDo.Data.Models.WorktreeState.Active;
             }
-
         }
         catch { /* best-effort */ }
     }
 
-    // Live-update a single improvement child's outcome row from a task event. No-op if the
-    // updated task isn't one of this parent's children.
     private async System.Threading.Tasks.Task RefreshChildOutcomeAsync(string childTaskId)
     {
         var row = ChildOutcomes.FirstOrDefault(c => c.Id == childTaskId);
@@ -1154,23 +879,12 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             row.Status = child.Status;
             row.RoadblockCount = child.RoadblockCount;
             row.WorktreeState = child.Worktree?.State ?? ClaudeDo.Data.Models.WorktreeState.Active;
-            ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
+            Merge.ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
             NotifyAttention();
         }
         catch { /* best-effort */ }
     }
 
-    [RelayCommand(CanExecute = nameof(CanReviewDiff))]
-    private async System.Threading.Tasks.Task ReviewCombinedDiffAsync()
-    {
-        if (Task is null || ShowPlanningDiffModal is null) return;
-        var vm = new ViewModels.Planning.PlanningDiffViewModel(_worker, Task.Id, SelectedMergeTarget ?? "main");
-        await vm.InitializeAsync();
-        await ShowPlanningDiffModal(vm);
-    }
-
-    private bool CanReviewDiff() => (Task?.IsPlanningParent == true && Subtasks.Any()) || HasChildOutcomes;
-
     private async System.Threading.Tasks.Task RefreshWorktreeAsync(string taskId)
     {
         try
@@ -1195,116 +909,29 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             var (add, del) = ParseDiffStat(entity.Worktree?.DiffStat);
             DiffAdditions = add;
             DiffDeletions = del;
+
+            Merge.SyncWorktree(WorktreePath, WorktreeBaseCommit, WorktreeHeadCommit,
+                WorktreeStateLabel, _listWorkingDir);
         }
         catch { /* best-effort refresh */ }
     }
 
-    private async System.Threading.Tasks.Task RefreshMergePreviewAsync()
-    {
-        if (Task is null || WorktreePath is null)
-        {
-            MergePreviewText = ""; MergeIsClean = false; MergeIsConflict = false;
-            return;
-        }
-        // Only probe Active worktrees; terminal states show their label instead.
-        if (WorktreeStateLabel is { } label && label != "Active")
-        {
-            MergePreviewText = label; MergeIsClean = false; MergeIsConflict = false;
-            return;
-        }
-        var capturedTaskId = Task.Id;
-        var capturedTarget = SelectedMergeTarget;
-        var dto = await _worker.PreviewMergeAsync(capturedTaskId, capturedTarget ?? "");
-        // Discard a probe that resolved after the user switched task or target.
-        if (Task?.Id != capturedTaskId || SelectedMergeTarget != capturedTarget) return;
-        var (text, clean, conflict) = MergePreviewPresenter.Describe(dto);
-        MergePreviewText = text; MergeIsClean = clean; MergeIsConflict = conflict;
-    }
-
-    [RelayCommand(CanExecute = nameof(CanOpenDiff))]
-    private async System.Threading.Tasks.Task OpenDiffAsync()
-    {
-        if (ShowDiffModal == null) return;
-        var git = _services.GetRequiredService<ClaudeDo.Data.Git.GitService>();
-
-        // Active worktree on disk → diff the worktree live (and allow merging from it).
-        var hasLiveWorktree =
-            WorktreePath != null
-            && WorktreeStateLabel == "Active"
-            && System.IO.Directory.Exists(WorktreePath);
-
-        DiffModalViewModel diffVm;
-        if (hasLiveWorktree)
-        {
-            diffVm = new DiffModalViewModel(git)
-            {
-                WorktreePath = WorktreePath!,
-                BaseRef = WorktreeBaseCommit,
-                TaskId = Task?.Id,
-                TaskTitle = Task?.Title ?? "",
-                ShowMergeModal = ShowMergeModal,
-                ResolveMergeVm = () => _services.GetRequiredService<MergeModalViewModel>(),
-            };
-        }
-        else if (CanDiffMergedRange)
-        {
-            // Worktree is gone (merged/discarded) but the commits survive on the
-            // target branch — diff the captured base..head range in the repo. No
-            // merge action: the work is already integrated.
-            diffVm = new DiffModalViewModel(git)
-            {
-                WorktreePath = _listWorkingDir!,
-                BaseRef = WorktreeBaseCommit,
-                HeadCommit = WorktreeHeadCommit,
-                FromCommitRange = true,
-                TaskId = Task?.Id,
-                TaskTitle = Task?.Title ?? "",
-            };
-        }
-        else return;
-
-        await diffVm.LoadAsync();
-        await ShowDiffModal(diffVm);
-    }
-
-    private bool CanDiffMergedRange =>
-        WorktreeBaseCommit != null && WorktreeHeadCommit != null && _listWorkingDir != null;
-
-    private bool CanOpenDiff() => WorktreePath != null || CanDiffMergedRange;
-
-    [RelayCommand(CanExecute = nameof(CanOpenWorktree))]
-    private void OpenWorktree()
-    {
-        if (WorktreePath == null) return;
-        try
-        {
-            System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
-            {
-                FileName = WorktreePath,
-                UseShellExecute = true,
-            });
-        }
-        catch { /* explorer open is best-effort */ }
-    }
-
-    private bool CanOpenWorktree() => WorktreePath != null;
-
-    partial void OnSelectedMergeTargetChanged(string? value)
-    {
-        _ = RefreshMergePreviewAsync();
-    }
-
     partial void OnWorktreePathChanged(string? value)
     {
-        OpenDiffCommand.NotifyCanExecuteChanged();
+        Merge.SyncWorktree(WorktreePath, WorktreeBaseCommit, WorktreeHeadCommit,
-        OpenWorktreeCommand.NotifyCanExecuteChanged();
+            WorktreeStateLabel, _listWorkingDir);
         NotifySessionSections();
     }
 
     partial void OnWorktreeHeadCommitChanged(string? value) =>
-        OpenDiffCommand.NotifyCanExecuteChanged();
+        Merge.SyncWorktree(WorktreePath, WorktreeBaseCommit, WorktreeHeadCommit,
+            WorktreeStateLabel, _listWorkingDir);
 
-    partial void OnTaskChanged(TaskRowViewModel? value) => NotifySessionSections();
+    partial void OnTaskChanged(TaskRowViewModel? value)
+    {
+        Merge.SyncTaskContext(Task?.Id, Task?.Title, Task?.IsPlanningParent == true);
+        NotifySessionSections();
+    }
 
     [RelayCommand]
     private void CloseDetails() => CloseDetail?.Invoke();
@@ -1370,7 +997,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             var repo = new TaskRepository(ctx);
             await repo.DeleteAsync(row.Id);
         }
-        catch (DbUpdateException ex) when (
+        catch (Microsoft.EntityFrameworkCore.DbUpdateException ex) when (
                ex.Message.Contains("FOREIGN KEY", StringComparison.OrdinalIgnoreCase)
             || ex.InnerException?.Message.Contains("FOREIGN KEY", StringComparison.OrdinalIgnoreCase) == true)
         {
@@ -1393,7 +1020,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         await using var ctx = _dbFactory.CreateDbContext();
         var repo = new SubtaskRepository(ctx);
 
-        // Emptying the text removes the step.
         if (string.IsNullOrEmpty(title))
         {
             await repo.DeleteAsync(row.Id);
@@ -1512,13 +1138,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     private bool CanResetAndRetry() =>
         Task != null && _worker.IsConnected && ShowResetAndRetry;
 
-    [RelayCommand] private void ResetTaskModel() => TaskModelSelection = null;
-    [RelayCommand] private void ResetTaskTurns() => TaskMaxTurns = null;
-    [RelayCommand] private void ResetTaskAgent() => TaskSelectedAgent = TaskAgentOptions.Count > 0 ? TaskAgentOptions[0] : null;
-
-    // ── Review actions ──────────────────────────────────────────────────────────
-    [ObservableProperty] private string _reviewFeedback = "";
-
     [RelayCommand]
     private async System.Threading.Tasks.Task ApproveReviewAsync()
     {
@@ -1526,26 +1145,25 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         try
         {
             var hasChildren = Subtasks.Count > 0 || ChildOutcomes.Count > 0;
-            var result = await _worker.ApproveReviewAsync(Task.Id, SelectedMergeTarget ?? "");
+            var result = await _worker.ApproveReviewAsync(Task.Id, Merge.SelectedMergeTarget ?? "");
             if (!hasChildren && result?.Status == "conflict")
             {
-                if (RequestConflictResolution is not null)
+                if (Merge.RequestConflictResolution is not null)
                 {
-                    await RequestConflictResolution(Task.Id, SelectedMergeTarget ?? "");
+                    await Merge.RequestConflictResolution(Task.Id, Merge.SelectedMergeTarget ?? "");
                 }
                 else
                 {
                     var (text, _, _) = MergePreviewPresenter.Describe(
                         new MergePreviewDto("conflict", result.ConflictFiles, 0));
-                    MergePreviewText = text; MergeIsClean = false; MergeIsConflict = true;
+                    Merge.MergePreviewText = text;
+                    Merge.MergeIsClean = false;
+                    Merge.MergeIsConflict = true;
                 }
             }
-            // hasChildren: conflicts arrive via PlanningMergeConflictEvent → conflict dialog
         }
         catch (Exception ex)
         {
-            // A real failure (e.g. a child still needs attention, so the unit can't
-            // be approved yet) must not vanish — tell the user why nothing happened.
             if (ShowErrorAsync != null)
                 await ShowErrorAsync(ex.Message);
         }
@@ -1582,7 +1200,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         catch { /* stale review action; broadcast reconciles */ }
     }
 
-    // ── Diff meter parser ───────────────────────────────────────────────────────
     internal static (int Additions, int Deletions) ParseDiffStat(string? stat)
     {
         if (string.IsNullOrEmpty(stat)) return (0, 0);

src/ClaudeDo.Ui/ViewModels/Islands/MergeSectionViewModel.cs

@@ -0,0 +1,200 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using System.Collections.ObjectModel;
+using ClaudeDo.Ui.Services;
+using ClaudeDo.Ui.ViewModels.Modals;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace ClaudeDo.Ui.ViewModels.Islands;
+
+public sealed partial class MergeSectionViewModel : ViewModelBase
+{
+    private readonly IWorkerClient _worker;
+    private readonly IServiceProvider _services;
+
+    // Context mirrored from parent, updated via Sync* methods
+    internal string? TaskId { get; private set; }
+    internal string? TaskTitle { get; private set; }
+    private string? _worktreePath;
+    private string? _worktreeBaseCommit;
+    private string? _worktreeHeadCommit;
+    private string? _worktreeStateLabel;
+    private string? _listWorkingDir;
+    private bool _isPlanningParent;
+    private int _subtaskCount;
+    private bool _hasChildOutcomes;
+
+    [ObservableProperty] private ObservableCollection<string> _mergeTargetBranches = new();
+    [ObservableProperty] private string? _selectedMergeTarget;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
+    private string _mergePreviewText = "";
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
+    private bool _mergeIsClean;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowMergePreviewMuted))]
+    private bool _mergeIsConflict;
+
+    public bool ShowMergePreviewMuted =>
+        !MergeIsClean && !MergeIsConflict && !string.IsNullOrEmpty(MergePreviewText);
+
+    public bool ShowMergeSection =>
+        _worktreePath != null || _isPlanningParent || _hasChildOutcomes;
+
+    public Func<DiffModalViewModel, System.Threading.Tasks.Task>? ShowDiffModal { get; set; }
+    public Func<MergeModalViewModel, System.Threading.Tasks.Task>? ShowMergeModal { get; set; }
+    public Func<ViewModels.Planning.PlanningDiffViewModel, System.Threading.Tasks.Task>? ShowPlanningDiffModal { get; set; }
+    public Func<string, string, System.Threading.Tasks.Task>? RequestConflictResolution { get; set; }
+
+    public MergeSectionViewModel(IWorkerClient worker, IServiceProvider services)
+    {
+        _worker = worker;
+        _services = services;
+    }
+
+    partial void OnSelectedMergeTargetChanged(string? value) => _ = RefreshMergePreviewAsync();
+
+    internal void SyncWorktree(
+        string? worktreePath,
+        string? worktreeBase,
+        string? worktreeHead,
+        string? worktreeState,
+        string? listWorkDir)
+    {
+        _worktreePath = worktreePath;
+        _worktreeBaseCommit = worktreeBase;
+        _worktreeHeadCommit = worktreeHead;
+        _worktreeStateLabel = worktreeState;
+        _listWorkingDir = listWorkDir;
+        OnPropertyChanged(nameof(ShowMergeSection));
+        OpenDiffCommand.NotifyCanExecuteChanged();
+        OpenWorktreeCommand.NotifyCanExecuteChanged();
+    }
+
+    internal void SyncTaskContext(string? taskId, string? taskTitle, bool isPlanningParent)
+    {
+        TaskId = taskId;
+        TaskTitle = taskTitle;
+        _isPlanningParent = isPlanningParent;
+        OnPropertyChanged(nameof(ShowMergeSection));
+    }
+
+    internal void SyncChildOutcomes(bool hasChildOutcomes, int subtaskCount)
+    {
+        _hasChildOutcomes = hasChildOutcomes;
+        _subtaskCount = subtaskCount;
+        OnPropertyChanged(nameof(ShowMergeSection));
+        ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
+    }
+
+    internal async System.Threading.Tasks.Task RefreshMergePreviewAsync()
+    {
+        if (TaskId is null || _worktreePath is null)
+        {
+            MergePreviewText = ""; MergeIsClean = false; MergeIsConflict = false;
+            return;
+        }
+        if (_worktreeStateLabel is { } label && label != "Active")
+        {
+            MergePreviewText = label; MergeIsClean = false; MergeIsConflict = false;
+            return;
+        }
+        var capturedTaskId = TaskId;
+        var capturedTarget = SelectedMergeTarget;
+        var dto = await _worker.PreviewMergeAsync(capturedTaskId, capturedTarget ?? "");
+        if (TaskId != capturedTaskId || SelectedMergeTarget != capturedTarget) return;
+        var (text, clean, conflict) = MergePreviewPresenter.Describe(dto);
+        MergePreviewText = text; MergeIsClean = clean; MergeIsConflict = conflict;
+    }
+
+    internal void Clear()
+    {
+        MergeTargetBranches.Clear();
+        SelectedMergeTarget = null;
+        MergePreviewText = "";
+        MergeIsClean = false;
+        MergeIsConflict = false;
+        SyncWorktree(null, null, null, null, null);
+        SyncTaskContext(null, null, false);
+        SyncChildOutcomes(false, 0);
+    }
+
+    [RelayCommand(CanExecute = nameof(CanReviewDiff))]
+    private async System.Threading.Tasks.Task ReviewCombinedDiffAsync()
+    {
+        if (TaskId is null || ShowPlanningDiffModal is null) return;
+        var vm = new ViewModels.Planning.PlanningDiffViewModel(_worker, TaskId, SelectedMergeTarget ?? "main");
+        await vm.InitializeAsync();
+        await ShowPlanningDiffModal(vm);
+    }
+
+    private bool CanReviewDiff() => (_isPlanningParent && _subtaskCount > 0) || _hasChildOutcomes;
+
+    [RelayCommand(CanExecute = nameof(CanOpenDiff))]
+    private async System.Threading.Tasks.Task OpenDiffAsync()
+    {
+        if (ShowDiffModal is null) return;
+        var git = _services.GetRequiredService<ClaudeDo.Data.Git.GitService>();
+
+        var hasLiveWorktree =
+            _worktreePath != null
+            && _worktreeStateLabel == "Active"
+            && System.IO.Directory.Exists(_worktreePath);
+
+        DiffModalViewModel diffVm;
+        if (hasLiveWorktree)
+        {
+            diffVm = new DiffModalViewModel(git)
+            {
+                WorktreePath = _worktreePath!,
+                BaseRef = _worktreeBaseCommit,
+                TaskId = TaskId,
+                TaskTitle = TaskTitle ?? "",
+                ShowMergeModal = ShowMergeModal,
+                ResolveMergeVm = () => _services.GetRequiredService<MergeModalViewModel>(),
+            };
+        }
+        else if (CanDiffMergedRange)
+        {
+            diffVm = new DiffModalViewModel(git)
+            {
+                WorktreePath = _listWorkingDir!,
+                BaseRef = _worktreeBaseCommit,
+                HeadCommit = _worktreeHeadCommit,
+                FromCommitRange = true,
+                TaskId = TaskId,
+                TaskTitle = TaskTitle ?? "",
+            };
+        }
+        else return;
+
+        await diffVm.LoadAsync();
+        await ShowDiffModal(diffVm);
+    }
+
+    private bool CanDiffMergedRange =>
+        _worktreeBaseCommit != null && _worktreeHeadCommit != null && _listWorkingDir != null;
+
+    private bool CanOpenDiff() => _worktreePath != null || CanDiffMergedRange;
+
+    [RelayCommand(CanExecute = nameof(CanOpenWorktree))]
+    private void OpenWorktree()
+    {
+        if (_worktreePath is null) return;
+        try
+        {
+            System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
+            {
+                FileName = _worktreePath,
+                UseShellExecute = true,
+            });
+        }
+        catch { }
+    }
+
+    private bool CanOpenWorktree() => _worktreePath != null;
+}

src/ClaudeDo.Ui/ViewModels/Islands/PrepPanelViewModel.cs

@@ -0,0 +1,102 @@
+using System.Collections.ObjectModel;
+using System.Text;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using ClaudeDo.Ui.Helpers;
+using ClaudeDo.Ui.Services;
+
+namespace ClaudeDo.Ui.ViewModels.Islands;
+
+public sealed partial class PrepPanelViewModel : ViewModelBase, IDisposable
+{
+    private readonly IWorkerClient _worker;
+    private readonly StreamLineFormatter _formatter = new();
+    private readonly StringBuilder _prepClaudeBuf = new();
+
+    private readonly Action _onPrepStartedHandler;
+    private readonly Action<string> _onPrepLineHandler;
+    private readonly Action<bool> _onPrepFinishedHandler;
+
+    [ObservableProperty] private bool _isPrepRunning;
+
+    public ObservableCollection<LogLineViewModel> PrepLog { get; } = new();
+
+    public bool ShowPrepEmptyState => !IsPrepRunning && PrepLog.Count == 0;
+
+    partial void OnIsPrepRunningChanged(bool value) => OnPropertyChanged(nameof(ShowPrepEmptyState));
+
+    public PrepPanelViewModel(IWorkerClient worker)
+    {
+        _worker = worker;
+        _onPrepStartedHandler = OnPrepStarted;
+        _onPrepLineHandler = OnPrepLine;
+        _onPrepFinishedHandler = OnPrepFinished;
+
+        _worker.PrepStartedEvent += _onPrepStartedHandler;
+        _worker.PrepLineEvent += _onPrepLineHandler;
+        _worker.PrepFinishedEvent += _onPrepFinishedHandler;
+
+        PrepLog.CollectionChanged += (_, _) => OnPropertyChanged(nameof(ShowPrepEmptyState));
+    }
+
+    public void Dispose()
+    {
+        _worker.PrepStartedEvent -= _onPrepStartedHandler;
+        _worker.PrepLineEvent -= _onPrepLineHandler;
+        _worker.PrepFinishedEvent -= _onPrepFinishedHandler;
+    }
+
+    [RelayCommand]
+    private async System.Threading.Tasks.Task PlanDayAsync()
+    {
+        try { await _worker.RunDailyPrepNowAsync(); }
+        catch { }
+    }
+
+    public async System.Threading.Tasks.Task LoadLastPrepLogIfEmptyAsync()
+    {
+        if (IsPrepRunning || PrepLog.Count > 0) return;
+        string text;
+        try { text = await _worker.GetLastPrepLogAsync(); }
+        catch { return; }
+        if (IsPrepRunning || PrepLog.Count > 0) return;
+        foreach (var line in text.Split('\n'))
+        {
+            var trimmed = line.TrimEnd('\r');
+            if (trimmed.Length > 0) AppendStdoutLine(trimmed);
+        }
+    }
+
+    private void OnPrepStarted()
+    {
+        PrepLog.Clear();
+        IsPrepRunning = true;
+    }
+
+    private void OnPrepLine(string line) => AppendStdoutLine(line);
+
+    private void OnPrepFinished(bool success) => IsPrepRunning = false;
+
+    private void AppendStdoutLine(string line)
+    {
+        var formatted = _formatter.FormatLine(line);
+        if (formatted is null) return;
+        AppendClaudeText(formatted);
+    }
+
+    private void AppendClaudeText(string chunk)
+    {
+        _prepClaudeBuf.Append(chunk);
+        while (true)
+        {
+            var text = _prepClaudeBuf.ToString();
+            var nl = text.IndexOf('\n');
+            if (nl < 0) break;
+            var piece = text[..nl].TrimEnd('\r');
+            if (!string.IsNullOrWhiteSpace(piece))
+                PrepLog.Add(new LogLineViewModel { Kind = LogKind.Claude, Text = piece });
+            _prepClaudeBuf.Clear();
+            _prepClaudeBuf.Append(text[(nl + 1)..]);
+        }
+    }
+}

src/ClaudeDo.Ui/Views/Islands/AgentStripView.axaml

@@ -138,8 +138,8 @@
 
       <!-- Action buttons -->
       <StackPanel Orientation="Horizontal" Spacing="6" Margin="0,4,0,0">
-        <Button Classes="btn" Content="{loc:Tr agent.openDiff}" Command="{Binding OpenDiffCommand}"/>
+        <Button Classes="btn" Content="{loc:Tr agent.openDiff}" Command="{Binding Merge.OpenDiffCommand}"/>
-        <Button Classes="btn" Command="{Binding OpenWorktreeCommand}"
+        <Button Classes="btn" Command="{Binding Merge.OpenWorktreeCommand}"
                 ToolTip.Tip="{loc:Tr agent.openWorktreeTip}">
           <StackPanel Orientation="Horizontal" Spacing="6" VerticalAlignment="Center">
             <PathIcon Data="{StaticResource Icon.ArrowOut}"

src/ClaudeDo.Ui/Views/Islands/Detail/TaskHeaderBar.axaml

@@ -52,7 +52,7 @@
     <!-- Column 2: gear button with agent settings flyout -->
     <Button Grid.Column="2" Classes="icon-btn"
             ToolTip.Tip="{loc:Tr details.agentSettingsTip}"
-            IsEnabled="{Binding IsAgentSectionEnabled}"
+            IsEnabled="{Binding AgentSettings.IsAgentSectionEnabled}"
             VerticalAlignment="Top"
             Margin="6,0,0,0">
       <TextBlock Text="⚙" FontSize="{StaticResource FontSizeTaskTitle}"/>
@@ -64,50 +64,50 @@
             <StackPanel Spacing="2">
               <Grid ColumnDefinitions="Auto,Auto,*,Auto" ColumnSpacing="6">
                 <TextBlock Grid.Column="0" Classes="field-label" Text="{loc:Tr details.modelLabel}" VerticalAlignment="Center"/>
-                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding ModelBadge}"/>
+                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding AgentSettings.ModelBadge}"/>
                 <Button Grid.Column="3" Classes="icon-btn" Content="↺" ToolTip.Tip="{loc:Tr settings.inherit.resetToInherited}"
-                        Command="{Binding ResetTaskModelCommand}"/>
+                        Command="{Binding AgentSettings.ResetTaskModelCommand}"/>
               </Grid>
-              <ComboBox ItemsSource="{Binding TaskModelOptions}"
+              <ComboBox ItemsSource="{Binding AgentSettings.TaskModelOptions}"
-                        SelectedItem="{Binding TaskModelSelection, Mode=TwoWay}"
+                        SelectedItem="{Binding AgentSettings.TaskModelSelection, Mode=TwoWay}"
-                        PlaceholderText="{Binding ModelInheritedHint}"
+                        PlaceholderText="{Binding AgentSettings.ModelInheritedHint}"
                         HorizontalAlignment="Stretch"/>
             </StackPanel>
 
             <StackPanel Spacing="2">
               <Grid ColumnDefinitions="Auto,Auto,*,Auto" ColumnSpacing="6">
                 <TextBlock Grid.Column="0" Classes="field-label" Text="{loc:Tr details.maxTurnsLabel}" VerticalAlignment="Center"/>
-                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding TurnsBadge}"/>
+                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding AgentSettings.TurnsBadge}"/>
                 <Button Grid.Column="3" Classes="icon-btn" Content="↺" ToolTip.Tip="{loc:Tr settings.inherit.resetToInherited}"
-                        Command="{Binding ResetTaskTurnsCommand}"/>
+                        Command="{Binding AgentSettings.ResetTaskTurnsCommand}"/>
               </Grid>
-              <NumericUpDown Value="{Binding TaskMaxTurns, Mode=TwoWay}"
+              <NumericUpDown Value="{Binding AgentSettings.TaskMaxTurns, Mode=TwoWay}"
-                             PlaceholderText="{Binding TurnsInheritedHint}"
+                             PlaceholderText="{Binding AgentSettings.TurnsInheritedHint}"
                              Minimum="1" Maximum="200" Increment="1" FormatString="0"
                              HorizontalAlignment="Stretch"/>
             </StackPanel>
 
             <StackPanel Spacing="2">
               <TextBlock Classes="field-label" Text="{loc:Tr details.systemPromptLabel}"/>
-              <TextBox Text="{Binding TaskSystemPrompt, Mode=TwoWay}"
+              <TextBox Text="{Binding AgentSettings.TaskSystemPrompt, Mode=TwoWay}"
                        AcceptsReturn="True" TextWrapping="Wrap" MinHeight="70"/>
               <TextBlock Classes="meta" Opacity="0.6"
                          Text="{loc:Tr details.systemPromptPrepended}"
-                         IsVisible="{Binding EffectiveSystemPromptHint, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+                         IsVisible="{Binding AgentSettings.EffectiveSystemPromptHint, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
               <TextBlock Classes="meta" Opacity="0.6" TextWrapping="Wrap"
-                         Text="{Binding EffectiveSystemPromptHint}"
+                         Text="{Binding AgentSettings.EffectiveSystemPromptHint}"
-                         IsVisible="{Binding EffectiveSystemPromptHint, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+                         IsVisible="{Binding AgentSettings.EffectiveSystemPromptHint, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
             </StackPanel>
 
             <StackPanel Spacing="2">
               <Grid ColumnDefinitions="Auto,Auto,*,Auto" ColumnSpacing="6">
                 <TextBlock Grid.Column="0" Classes="field-label" Text="{loc:Tr details.agentFileLabel}" VerticalAlignment="Center"/>
-                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding AgentBadge}"/>
+                <ctl:InheritedBadge Grid.Column="1" BadgeText="{Binding AgentSettings.AgentBadge}"/>
                 <Button Grid.Column="3" Classes="icon-btn" Content="↺" ToolTip.Tip="{loc:Tr settings.inherit.resetToInherited}"
-                        Command="{Binding ResetTaskAgentCommand}"/>
+                        Command="{Binding AgentSettings.ResetTaskAgentCommand}"/>
               </Grid>
-              <ComboBox ItemsSource="{Binding TaskAgentOptions}"
+              <ComboBox ItemsSource="{Binding AgentSettings.TaskAgentOptions}"
-                        SelectedItem="{Binding TaskSelectedAgent, Mode=TwoWay}"
+                        SelectedItem="{Binding AgentSettings.TaskSelectedAgent, Mode=TwoWay}"
                         HorizontalAlignment="Stretch">
                 <ComboBox.ItemTemplate>
                   <DataTemplate>

src/ClaudeDo.Ui/Views/Islands/Detail/WorkConsole.axaml

@@ -266,26 +266,26 @@
 
         <!-- Git: one Approve + merge cockpit -->
         <ScrollViewer IsVisible="{Binding IsGitTab}" Padding="14,10">
-          <StackPanel Spacing="12" IsVisible="{Binding ShowMergeSection}">
+          <StackPanel Spacing="12" IsVisible="{Binding Merge.ShowMergeSection}">
             <TextBlock Classes="section-label" Text="MERGE" />
 
             <StackPanel Spacing="4">
               <TextBlock Classes="field-label" Text="Target branch" />
-              <ComboBox ItemsSource="{Binding MergeTargetBranches}"
+              <ComboBox ItemsSource="{Binding Merge.MergeTargetBranches}"
-                        SelectedItem="{Binding SelectedMergeTarget, Mode=TwoWay}"
+                        SelectedItem="{Binding Merge.SelectedMergeTarget, Mode=TwoWay}"
                         HorizontalAlignment="Stretch" />
             </StackPanel>
 
             <StackPanel Spacing="0">
-              <TextBlock Classes="meta" Text="{Binding MergePreviewText}" TextWrapping="Wrap"
+              <TextBlock Classes="meta" Text="{Binding Merge.MergePreviewText}" TextWrapping="Wrap"
                          Foreground="{DynamicResource MossBrush}"
-                         IsVisible="{Binding MergeIsClean}" />
+                         IsVisible="{Binding Merge.MergeIsClean}" />
-              <TextBlock Classes="meta" Text="{Binding MergePreviewText}" TextWrapping="Wrap"
+              <TextBlock Classes="meta" Text="{Binding Merge.MergePreviewText}" TextWrapping="Wrap"
                          Foreground="{DynamicResource BloodBrush}"
-                         IsVisible="{Binding MergeIsConflict}" />
+                         IsVisible="{Binding Merge.MergeIsConflict}" />
-              <TextBlock Classes="meta" Text="{Binding MergePreviewText}" TextWrapping="Wrap"
+              <TextBlock Classes="meta" Text="{Binding Merge.MergePreviewText}" TextWrapping="Wrap"
                          Foreground="{DynamicResource TextMuteBrush}"
-                         IsVisible="{Binding ShowMergePreviewMuted}" />
+                         IsVisible="{Binding Merge.ShowMergePreviewMuted}" />
             </StackPanel>
 
             <!-- Primary action: Approve flows straight into the merge. -->
@@ -294,17 +294,17 @@
                       Command="{Binding ApproveReviewCommand}"
                       IsVisible="{Binding IsWaitingForReview}" />
               <Button Classes="btn" Content="Open Diff" Margin="0,0,8,8"
-                      Command="{Binding OpenDiffCommand}" />
+                      Command="{Binding Merge.OpenDiffCommand}" />
               <Button Classes="btn" Margin="0,0,8,8"
                       ToolTip.Tip="{loc:Tr agent.openWorktreeTip}"
-                      Command="{Binding OpenWorktreeCommand}">
+                      Command="{Binding Merge.OpenWorktreeCommand}">
                 <StackPanel Orientation="Horizontal" Spacing="5">
                   <TextBlock Text="Worktree" />
                   <PathIcon Data="{StaticResource Icon.ArrowOut}" Width="11" Height="11" />
                 </StackPanel>
               </Button>
               <Button Classes="btn" Content="Review Combined Diff" Margin="0,0,8,8"
-                      Command="{Binding ReviewCombinedDiffCommand}" />
+                      Command="{Binding Merge.ReviewCombinedDiffCommand}" />
             </WrapPanel>
           </StackPanel>
         </ScrollViewer>

src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml

@@ -104,16 +104,16 @@
         <DockPanel>
           <Border DockPanel.Dock="Top" Padding="12,8">
             <Button Classes="btn primary"
-                    Command="{Binding PlanDayCommand}"
+                    Command="{Binding Prep.PlanDayCommand}"
-                    IsEnabled="{Binding !IsPrepRunning}"
+                    IsEnabled="{Binding !Prep.IsPrepRunning}"
                     Content="{loc:Tr details.planDay}"/>
           </Border>
           <Panel>
             <islands:SessionTerminalView
                 Margin="18,8,18,0"
-                Entries="{Binding PrepLog}" Label="daily-prep"
+                Entries="{Binding Prep.PrepLog}" Label="daily-prep"
-                IsRunning="{Binding IsPrepRunning}"/>
+                IsRunning="{Binding Prep.IsPrepRunning}"/>
-            <TextBlock IsVisible="{Binding ShowPrepEmptyState}"
+            <TextBlock IsVisible="{Binding Prep.ShowPrepEmptyState}"
                        HorizontalAlignment="Center" VerticalAlignment="Center"
                        Foreground="{DynamicResource TextMuteBrush}"
                        Text="{loc:Tr details.prepEmpty}"/>

src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml.cs

@@ -48,7 +48,7 @@ public partial class DetailsIslandView : UserControl
             vm.PropertyChanged += OnViewModelPropertyChanged;
             ApplyResizeStateForCurrentTask();
 
-            vm.ShowDiffModal = async (diffVm) =>
+            vm.Merge.ShowDiffModal = async (diffVm) =>
             {
                 var owner = TopLevel.GetTopLevel(this) as Window;
                 if (owner == null) return;
@@ -56,7 +56,7 @@ public partial class DetailsIslandView : UserControl
                 await modal.ShowDialog(owner);
             };
 
-            vm.ShowMergeModal = async (mergeVm) =>
+            vm.Merge.ShowMergeModal = async (mergeVm) =>
             {
                 var owner = TopLevel.GetTopLevel(this) as Window;
                 if (owner == null) return;
@@ -64,7 +64,7 @@ public partial class DetailsIslandView : UserControl
                 await modal.ShowDialog(owner);
             };
 
-            vm.ShowPlanningDiffModal = async (planningDiffVm) =>
+            vm.Merge.ShowPlanningDiffModal = async (planningDiffVm) =>
             {
                 var owner = TopLevel.GetTopLevel(this) as Window;
                 if (owner == null) return;

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

@@ -77,11 +77,11 @@ public class DetailsIslandConflictSeamTests : IDisposable
 
         var vm = BuildVm(new ConflictApproveWorkerClient());
         vm.Bind(new TaskRowViewModel { Id = taskId, Status = TaskStatus.WaitingForReview });
-        vm.SelectedMergeTarget = "main";
+        vm.Merge.SelectedMergeTarget = "main";
 
         string? capturedTaskId = null;
         string? capturedTarget = null;
-        vm.RequestConflictResolution = (tid, target) =>
+        vm.Merge.RequestConflictResolution = (tid, target) =>
         {
             capturedTaskId = tid;
             capturedTarget = target;

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

@@ -140,11 +140,11 @@ public class DetailsIslandPlanningTests : IDisposable
 
         // Wait for the background load to settle
         var deadline = DateTime.UtcNow.AddSeconds(5);
-        while (DateTime.UtcNow < deadline && vm.MergeTargetBranches.Count == 0)
+        while (DateTime.UtcNow < deadline && vm.Merge.MergeTargetBranches.Count == 0)
             await Task.Delay(20);
 
-        Assert.Contains("main", vm.MergeTargetBranches);
+        Assert.Contains("main", vm.Merge.MergeTargetBranches);
-        Assert.Contains("dev",  vm.MergeTargetBranches);
+        Assert.Contains("dev",  vm.Merge.MergeTargetBranches);
-        Assert.Equal("main", vm.SelectedMergeTarget);
+        Assert.Equal("main", vm.Merge.SelectedMergeTarget);
     }
 }

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

@@ -67,7 +67,7 @@ public class DetailsIslandPrepModeTests : IDisposable
 
         stub.RaisePrepLine("{\"type\":\"assistant\",\"message\":{\"content\":[{\"type\":\"text\",\"text\":\"hi\"}]}}");
 
-        Assert.NotEmpty(vm.PrepLog);
+        Assert.NotEmpty(vm.Prep.PrepLog);
     }
 
     [Fact]
@@ -88,9 +88,9 @@ public class DetailsIslandPrepModeTests : IDisposable
         var vm = NewDetailsVm(stub);
 
         vm.ShowPrep();
-        await vm.LoadLastPrepLogIfEmptyAsync();
+        await vm.Prep.LoadLastPrepLogIfEmptyAsync();
 
-        Assert.NotEmpty(vm.PrepLog);
+        Assert.NotEmpty(vm.Prep.PrepLog);
     }
 
     [Fact]
@@ -98,7 +98,7 @@ public class DetailsIslandPrepModeTests : IDisposable
     {
         var stub = new DefaultStub();
         var vm = NewDetailsVm(stub);
-        await vm.PlanDayCommand.ExecuteAsync(null);
+        await vm.Prep.PlanDayCommand.ExecuteAsync(null);
         Assert.Equal(1, stub.RunDailyPrepNowCalls);
     }
 
@@ -106,6 +106,6 @@ public class DetailsIslandPrepModeTests : IDisposable
     public void ShowPrepEmptyState_true_when_empty_and_not_running()
     {
         var vm = NewDetailsVm(new DefaultStub());
-        Assert.True(vm.ShowPrepEmptyState);
+        Assert.True(vm.Prep.ShowPrepEmptyState);
     }
 }