feat(planning): consolidate finalize+chain via TaskStateService, fix queue pickup

Slice 4 of the worker state consolidation refactor. Eliminates the
"queue never picks up planning tasks" bug structurally by routing both
the manager and MCP finalize paths through TaskStateService and
PlanningChainCoordinator.SetupChainAsync, where the auto-wake on enqueue
guarantees the queue picker claims the first child immediately.

- Delete TaskRepository.FinalizePlanningAsync; PlanningSessionManager
  now orchestrates via _state.FinalizePlanningAsync + _chain.SetupChainAsync.
- Rename QueueSubtasksSequentiallyAsync to SetupChainAsync (internal);
  layout is now Status=Queued + BlockedByTaskId, with auto-attached agent tag.
- OnChildFinishedAsync looks up the successor by BlockedByTaskId, drops
  the legacy Waiting status lookup.
- PlanningMcpService.Finalize routes through state+chain; EditableStatuses
  drops Waiting and adds Idle; gate uses PlanningPhase==Active.
- TaskStateService.FinalizePlanningAsync clears the planning session token.
- UI: TaskRowViewModel adds BlockedByTaskId; IsQueued/IsWaiting reflect
  the new layout; TasksIslandViewModel.RemoveFromQueueAsync clears
  BlockedByTaskId on dequeue.
- New regression test PlanningEndToEndTests.FinalizeAsync_FirstChildIs
  ClaimedByPicker_WithinDeadline asserts the picker claims the first
  child within 200ms with no manual WakeQueue.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Worker/Planning/PlanningMcpService.cs

@@ -2,6 +2,7 @@ using System.ComponentModel;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Hub;
+using ClaudeDo.Worker.State;
 using ModelContextProtocol.Server;
 using TaskStatus = ClaudeDo.Data.Models.TaskStatus;
 
@@ -16,15 +17,21 @@ public sealed class PlanningMcpService
     private readonly TaskRepository _tasks;
     private readonly PlanningMcpContextAccessor _contextAccessor;
     private readonly HubBroadcaster _broadcaster;
+    private readonly ITaskStateService _state;
+    private readonly PlanningChainCoordinator _chain;
 
     public PlanningMcpService(
         TaskRepository tasks,
         PlanningMcpContextAccessor contextAccessor,
-        HubBroadcaster broadcaster)
+        HubBroadcaster broadcaster,
+        ITaskStateService state,
+        PlanningChainCoordinator chain)
     {
         _tasks = tasks;
         _contextAccessor = contextAccessor;
         _broadcaster = broadcaster;
+        _state = state;
+        _chain = chain;
     }
 
     private Task BroadcastTaskUpdatedAsync(string taskId, CancellationToken ct)
@@ -61,9 +68,9 @@ public sealed class PlanningMcpService
     }
 
     private static readonly TaskStatus[] EditableStatuses =
-        { TaskStatus.Draft, TaskStatus.Manual, TaskStatus.Queued, TaskStatus.Waiting };
+        { TaskStatus.Draft, TaskStatus.Idle, TaskStatus.Manual, TaskStatus.Queued };
 
-    [McpServerTool, Description("Update a child task in the active planning session. Can change title, description, tags (replaces the full set), commit type, and status. Status must be one of: Draft, Manual, Queued, Waiting.")]
+    [McpServerTool, Description("Update a child task in the active planning session. Can change title, description, tags (replaces the full set), commit type, and status. Status must be one of: Draft, Idle, Manual, Queued.")]
     public async Task<ChildTaskDto> UpdateChildTask(
         string taskId,
         string? title,
@@ -76,7 +83,7 @@ public sealed class PlanningMcpService
         var ctx = _contextAccessor.Current;
         var parent = await _tasks.GetByIdAsync(ctx.ParentTaskId, cancellationToken)
             ?? throw new InvalidOperationException("Planning parent task not found.");
-        if (parent.Status != TaskStatus.Planning)
+        if (parent.PlanningPhase != PlanningPhase.Active)
             throw new InvalidOperationException("Cannot modify tasks outside an active planning session.");
 
         var child = await _tasks.GetByIdAsync(taskId, cancellationToken)
@@ -90,7 +97,7 @@ public sealed class PlanningMcpService
             if (!Enum.TryParse<TaskStatus>(status, ignoreCase: true, out var parsed))
                 throw new InvalidOperationException($"Unknown status '{status}'.");
             if (!EditableStatuses.Contains(parsed))
-                throw new InvalidOperationException($"Status '{parsed}' cannot be set via MCP. Allowed: Draft, Manual, Queued, Waiting.");
+                throw new InvalidOperationException($"Status '{parsed}' cannot be set via MCP. Allowed: Draft, Idle, Manual, Queued.");
             newStatus = parsed;
         }
 
@@ -111,7 +118,7 @@ public sealed class PlanningMcpService
         var ctx = _contextAccessor.Current;
         var parent = await _tasks.GetByIdAsync(ctx.ParentTaskId, cancellationToken)
             ?? throw new InvalidOperationException("Planning parent task not found.");
-        if (parent.Status != TaskStatus.Planning)
+        if (parent.PlanningPhase != PlanningPhase.Active)
             throw new InvalidOperationException("Cannot delete tasks outside an active planning session.");
 
         var child = await _tasks.GetByIdAsync(taskId, cancellationToken)
@@ -141,11 +148,19 @@ public sealed class PlanningMcpService
         CancellationToken cancellationToken)
     {
         var ctx = _contextAccessor.Current;
-        var childIds = (await _tasks.GetChildrenAsync(ctx.ParentTaskId, cancellationToken))
-            .Select(c => c.Id).ToList();
-        var count = await _tasks.FinalizePlanningAsync(ctx.ParentTaskId, queueAgentTasks, cancellationToken);
-        foreach (var id in childIds)
-            await BroadcastTaskUpdatedAsync(id, cancellationToken);
+
+        var finalizeResult = await _state.FinalizePlanningAsync(ctx.ParentTaskId, cancellationToken);
+        if (!finalizeResult.Ok)
+            throw new InvalidOperationException(
+                finalizeResult.Reason ?? $"Could not finalize planning for task {ctx.ParentTaskId}.");
+
+        var children = await _tasks.GetChildrenAsync(ctx.ParentTaskId, cancellationToken);
+        int count = children.Count;
+        if (queueAgentTasks && children.Count > 0)
+            count = await _chain.SetupChainAsync(ctx.ParentTaskId, cancellationToken);
+
+        foreach (var c in children)
+            await BroadcastTaskUpdatedAsync(c.Id, cancellationToken);
         await BroadcastTaskUpdatedAsync(ctx.ParentTaskId, cancellationToken);
         return count;
     }