feat(worker): add pre-flight checks and idempotent restart to PlanningMergeOrchestrator

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Worker/Planning/PlanningMergeOrchestrator.cs

@@ -1,5 +1,6 @@
 using System.Collections.Concurrent;
 using ClaudeDo.Data;
+using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Services;
@@ -14,6 +15,7 @@ public sealed class PlanningMergeOrchestrator
     private readonly TaskMergeService _merge;
     private readonly PlanningAggregator _aggregator;
     private readonly HubBroadcaster _broadcaster;
+    private readonly GitService _git;
     private readonly ILogger<PlanningMergeOrchestrator> _logger;
 
     private sealed class State
@@ -30,30 +32,53 @@ public sealed class PlanningMergeOrchestrator
         TaskMergeService merge,
         PlanningAggregator aggregator,
         HubBroadcaster broadcaster,
+        GitService git,
         ILogger<PlanningMergeOrchestrator> logger)
     {
         _dbFactory = dbFactory;
         _merge = merge;
         _aggregator = aggregator;
         _broadcaster = broadcaster;
+        _git = git;
         _logger = logger;
     }
 
     public async Task StartAsync(string planningTaskId, string targetBranch, CancellationToken ct)
     {
+        string workingDir;
         List<TaskEntity> children;
+
         using (var ctx = _dbFactory.CreateDbContext())
         {
-            children = await ctx.Tasks
-                .Include(t => t.Worktree)
-                .Where(t => t.ParentTaskId == planningTaskId)
-                .OrderBy(t => t.SortOrder)
-                .ToListAsync(ct);
+            var planning = await ctx.Tasks
+                .Include(t => t.List)
+                .Include(t => t.Children).ThenInclude(c => c.Worktree)
+                .SingleOrDefaultAsync(t => t.Id == planningTaskId, ct)
+                ?? throw new KeyNotFoundException($"Planning task '{planningTaskId}' not found.");
+            workingDir = planning.List.WorkingDir
+                ?? throw new InvalidOperationException("List has no working directory.");
+            children = planning.Children.OrderBy(c => c.SortOrder).ToList();
         }
 
+        foreach (var c in children)
+        {
+            if (c.Status != TaskStatus.Done)
+                throw new InvalidOperationException($"subtask {c.Id} is not Done (status {c.Status})");
+            if (c.Worktree is null)
+                throw new InvalidOperationException($"subtask {c.Id} has no worktree");
+            if (c.Worktree.State != WorktreeState.Active && c.Worktree.State != WorktreeState.Merged)
+                throw new InvalidOperationException(
+                    $"subtask {c.Id} worktree state is {c.Worktree.State}");
+        }
+
+        if (await _git.IsMidMergeAsync(workingDir, ct))
+            throw new InvalidOperationException("repo is mid-merge");
+        if (await _git.HasChangesAsync(workingDir, ct))
+            throw new InvalidOperationException("working tree has uncommitted changes");
+
         var queue = new Queue<string>(
             children
-                .Where(c => c.Worktree is not null && c.Worktree.State != WorktreeState.Merged)
+                .Where(c => c.Worktree!.State == WorktreeState.Active)
                 .Select(c => c.Id));
 
         var state = new State { TargetBranch = targetBranch, RemainingSubtaskIds = queue };