feat(ui): triage model picker (opus/fable) in the merge helper start modal

src/ClaudeDo.Localization/locales/de.json

@@ -497,6 +497,8 @@
       "windowTitle": "Claude machen lassen",
       "scopeList": "Liste: {0}",
       "scopeReview": "Alle Listen — Tasks im Review",
+      "modelLabel": "Modell",
+      "modelTip": "Modell für die Triage-Session (Dedupe & Verfeinern). Spätere Merge-Phasen laufen immer auf Opus.",
       "confirm": "Claude machen lassen",
       "cancel": "Abbrechen",
       "selectAll": "Alle auswählen",

src/ClaudeDo.Localization/locales/en.json

@@ -497,6 +497,8 @@
       "windowTitle": "Let Claude handle it",
       "scopeList": "List: {0}",
       "scopeReview": "All lists — tasks waiting for review",
+      "modelLabel": "Model",
+      "modelTip": "Model for the triage session (dedupe & refine). Later merge phases always run on opus.",
       "confirm": "Let Claude handle it",
       "cancel": "Cancel",
       "selectAll": "Select all",

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

@@ -143,8 +143,9 @@ public interface IWorkerClient : INotifyPropertyChanged
     /// <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
-    /// can call handoff_list_handler on its own handler task.</summary>
-    Task<LaunchSpec> GetMergeHelperLaunchSpecAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, CancellationToken ct = default);
+    /// can call handoff_list_handler on its own handler task. model overrides the triage
+    /// session's model (null = default).</summary>
+    Task<LaunchSpec> GetMergeHelperLaunchSpecAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, string? model = null, CancellationToken ct = default);
     /// <summary>Creates the ClaudeDo task that owns a list-handler run (one per run, Idle/IsManual,
     /// never queued) so the ConPTY tile can be task-based instead of ad-hoc. Returns the new task id.</summary>
     Task<string> CreateMergeHelperTaskAsync(

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -627,8 +627,8 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, CancellationToken ct = default)
         => await InvokeTimedAsync<LaunchSpec>("GetAdHocLaunchSpec", () => _hub.InvokeAsync<LaunchSpec>("GetAdHocLaunchSpec", directory, ct));
 
-    public async Task<LaunchSpec> GetMergeHelperLaunchSpecAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, CancellationToken ct = default)
-        => await InvokeTimedAsync<LaunchSpec>("GetMergeHelperLaunchSpec", () => _hub.InvokeAsync<LaunchSpec>("GetMergeHelperLaunchSpec", taskIds, listId, handlerTaskId, 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));
 
     public async Task<string> CreateMergeHelperTaskAsync(
         IReadOnlyList<string> taskIds, string listId, string title, string descriptionHeader, CancellationToken ct = default)

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

@@ -17,8 +17,9 @@ namespace ClaudeDo.Ui.ViewModels.Islands;
 
 public enum ListKind { Smart, Virtual, User }
 
-/// <summary>Confirmed handler run: the scope list and the ordered selected task ids.</summary>
-public sealed record MergeHelperRequest(string ListId, IReadOnlyList<string> TaskIds);
+/// <summary>Confirmed handler run: the scope list, the ordered selected task ids, and the model
+/// picked for the triage session (null = default; review-mode runs skip triage entirely).</summary>
+public sealed record MergeHelperRequest(string ListId, IReadOnlyList<string> TaskIds, string? TriageModel = null);
 
 public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
 {
@@ -114,7 +115,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
         await vm.LoadAsync();
         var ids = await Dialogs.ShowMergeHelperSelectionAsync(vm);
         if (ids is { Count: > 0 })
-            LetClaudeHandleRequested?.Invoke(new MergeHelperRequest(rawId, ids));
+            LetClaudeHandleRequested?.Invoke(new MergeHelperRequest(rawId, ids, vm.SelectedModel));
     }
 
     /// <summary>Raised once per list after the review-scoped selection dialog is confirmed;

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -370,7 +370,7 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
         Lists.LetClaudeHandleRequested += req =>
         {
             OpenMissionControl();
-            _ = MissionControl.OpenMergeHelperConPtySessionAsync(req.ListId, req.TaskIds);
+            _ = MissionControl.OpenMergeHelperConPtySessionAsync(req.ListId, req.TaskIds, req.TriageModel);
         };
         Lists.MergeReviewsRequested += req =>
         {

src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs

@@ -331,10 +331,10 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
     // creates one new ClaudeDo task per run to own the session (title/diff/result), deduped by
     // TaskId like OpenConPtySessionAsync. The handler still merges the tasks it handles itself
     // (no worktree of its own) — see TaskEntity.HandlerBaseCommit/HandlerHeadCommit.
-    public System.Threading.Tasks.Task OpenMergeHelperConPtySessionAsync(string listId, IReadOnlyList<string> taskIds)
+    public System.Threading.Tasks.Task OpenMergeHelperConPtySessionAsync(string listId, IReadOnlyList<string> taskIds, string? triageModel = null)
         => OpenListHandlerConPtySessionAsync(listId, taskIds,
             "missionControl.mergeHelperTitle", "missionControl.mergeHelperTaskTitle",
-            taskId => _worker.GetMergeHelperLaunchSpecAsync(taskIds, listId, taskId));
+            taskId => _worker.GetMergeHelperLaunchSpecAsync(taskIds, listId, taskId, triageModel));
 
     // Merge-only list-handler session over a list's WaitingForReview tasks (the review list's
     // "Let Claude merge the reviews"). Same host-task shape as the full run, but the session

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

@@ -67,6 +67,15 @@ public sealed partial class MergeHelperSelectionModalViewModel : ViewModelBase
 
     public ObservableCollection<MergeHelperTaskRowViewModel> Tasks { get; } = new();
 
+    /// <summary>Model choices for the triage session. Only opus/fable are offered on purpose —
+    /// triage is the dedupe/refine leverage point; cheaper models aren't worth a picker slot.</summary>
+    public IReadOnlyList<string> ModelOptions { get; } = new[] { "opus", "fable" };
+
+    [ObservableProperty] private string _selectedModel = Data.Models.ModelRegistry.HandlerTriageAlias;
+
+    /// <summary>Hidden in review mode — those runs start directly at the merge phase, no triage.</summary>
+    public bool ShowModelPicker => !_reviewMode;
+
     [ObservableProperty] private string _scopeLabel = "";
 
     public bool HasTasks => Tasks.Count > 0;
@@ -100,6 +109,7 @@ public sealed partial class MergeHelperSelectionModalViewModel : ViewModelBase
     {
         _reviewMode = true;
         ScopeLabel = Loc.T("modals.mergeHelper.scopeReview");
+        OnPropertyChanged(nameof(ShowModelPicker));
     }
 
     /// <summary>Groups a confirmed review-mode selection by owning list, preserving row order —

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

@@ -29,11 +29,18 @@
 
     <!-- Body: scope + select-all/none toolbar, headers, checkbox rows -->
     <DockPanel>
-      <Grid DockPanel.Dock="Top" ColumnDefinitions="*,Auto,Auto" Margin="20,12,20,6">
+      <Grid DockPanel.Dock="Top" ColumnDefinitions="*,Auto,Auto,Auto" Margin="20,12,20,6">
         <TextBlock Grid.Column="0" Classes="meta" Text="{Binding ScopeLabel}" VerticalAlignment="Center"/>
-        <Button Grid.Column="1" Classes="btn" Content="{loc:Tr modals.mergeHelper.selectAll}"
+        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="6" Margin="0,0,12,0"
+                    IsVisible="{Binding ShowModelPicker}"
+                    ToolTip.Tip="{loc:Tr modals.mergeHelper.modelTip}">
+          <TextBlock Classes="meta" Text="{loc:Tr modals.mergeHelper.modelLabel}" VerticalAlignment="Center"/>
+          <ComboBox MinWidth="90" ItemsSource="{Binding ModelOptions}"
+                    SelectedItem="{Binding SelectedModel, Mode=TwoWay}"/>
+        </StackPanel>
+        <Button Grid.Column="2" Classes="btn" Content="{loc:Tr modals.mergeHelper.selectAll}"
                 Command="{Binding SelectAllCommand}" IsEnabled="{Binding HasTasks}"/>
-        <Button Grid.Column="2" Classes="btn" Content="{loc:Tr modals.mergeHelper.selectNone}"
+        <Button Grid.Column="3" Classes="btn" Content="{loc:Tr modals.mergeHelper.selectNone}"
                 Command="{Binding SelectNoneCommand}" IsEnabled="{Binding HasTasks}" Margin="8,0,0,0"/>
       </Grid>
 

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -770,12 +770,13 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     // Builds the launch spec for an embedded ConPTY "merge helper" session that drives the given
     // tasks to a merged/Done state via the mcp__claudedo__* tools. listId scopes the brief label
     // and cwd to that list. handlerTaskId is the id returned by CreateMergeHelperTask -- it is
-    // rendered into the brief so the session can call handoff_list_handler on itself.
-    public Task<LaunchSpec> GetMergeHelperLaunchSpec(string[] taskIds, string listId, string handlerTaskId) => HubGuard(() =>
+    // rendered into the brief so the session can call handoff_list_handler on itself. model
+    // overrides the triage session's model (null = default opus).
+    public Task<LaunchSpec> GetMergeHelperLaunchSpec(string[] taskIds, string listId, string handlerTaskId, string? model) => HubGuard(() =>
     {
         if (_interactiveLaunchSpec is null)
             throw new InvalidOperationException("Interactive launch spec service is not configured.");
-        return _interactiveLaunchSpec.BuildForMergeHelperAsync(taskIds, listId, handlerTaskId, Context.ConnectionAborted);
+        return _interactiveLaunchSpec.BuildForMergeHelperAsync(taskIds, listId, handlerTaskId, model, Context.ConnectionAborted);
     });
 
     // Creates the ClaudeDo task that owns a list-handler run, before the ConPTY tile opens --

src/ClaudeDo.Worker/Runner/InteractiveLaunchSpecService.cs

@@ -290,8 +290,10 @@ public sealed class InteractiveLaunchSpecService
     /// handlerTaskId (the id returned by CreateMergeHelperTaskAsync) is rendered into the brief so
     /// the session can call handoff_list_handler/submit_task_for_review on its own handler task.
     /// Throws KeyNotFoundException if the list doesn't exist; InvalidOperationException if
-    /// taskIds is empty or the list has no existing working directory.</summary>
-    public async Task<LaunchSpec> BuildForMergeHelperAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, CancellationToken ct)
+    /// taskIds is empty or the list has no existing working directory.
+    /// model overrides the triage session's model (start-modal dropdown); null/unknown falls
+    /// back to <see cref="ModelRegistry.HandlerTriageAlias"/>. Handoff phases are unaffected.</summary>
+    public async Task<LaunchSpec> BuildForMergeHelperAsync(IReadOnlyList<string> taskIds, string listId, string handlerTaskId, string? model, CancellationToken ct)
     {
         if (taskIds.Count == 0)
             throw new InvalidOperationException("No tasks selected for the list handler.");
@@ -344,12 +346,13 @@ public sealed class InteractiveLaunchSpecService
         // longer influences a handler session at all, it would otherwise apply the LIST's effort
         // preset to a completely different model.
         var settings = await new AppSettingsRepository(ctx).GetAsync(ct);
+        var triageModel = ModelRegistry.TryNormalizeAlias(model) ?? ModelRegistry.HandlerTriageAlias;
 
         var args = new List<string>
         {
-            "--model", ModelRegistry.HandlerTriageAlias,
-            "--effort", EffortFor(settings, ModelRegistry.HandlerTriageAlias),
-            "--permission-mode", PermissionModeResolver.Resolve(ModelRegistry.HandlerTriageAlias, "auto"),
+            "--model", triageModel,
+            "--effort", EffortFor(settings, triageModel),
+            "--permission-mode", PermissionModeResolver.Resolve(triageModel, "auto"),
             "--allowedTools", MergeHelperAllowedTools,
             "--add-dir", sessionDir, repoDir,
             "--append-system-prompt-file", systemPromptPath,