feat(queue): warn when the base branch has uncommitted changes

Queuing (update_task_status, batch_update_task_status) and run_task_now
now surface a non-blocking baseDirty warning (separate modified/untracked
counts) when the list's working dir has uncommitted changes at enqueue
time, since a new worktree forks from the commit tip and silently misses
them. BaseDirtyChecker caches per working dir for a few seconds so a
batch queue over many tasks in one list only shells out to git once. The
UI surfaces the same warning via the footer error strip on queue actions.

src/ClaudeDo.Worker/External/ExternalMcpService.cs

@@ -7,6 +7,7 @@ using ClaudeDo.Data;
 using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Git;
 using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Lifecycle;
 using ClaudeDo.Worker.Planning;
@@ -26,7 +27,7 @@ public sealed record CancelTaskResult(bool Cancelled, string Id);
 // review range (worktree ahead, or HandlerBaseCommit..HandlerHeadCommit for a worktree-less
 // child) contributed nothing, so a reviewer sees them before approving instead of after.
 public sealed record ReviewTaskResult(TaskRefDto Task, string? MergeStatus, IReadOnlyList<string> MergeConflicts, string? MergeMessage, string? RepoPath = null, IReadOnlyList<TaskRefDto>? EmptyChildren = null);
-public sealed record RunTaskNowResult(bool Started, string TaskId);
+public sealed record RunTaskNowResult(bool Started, string TaskId, DirtyBaseWarning? BaseDirty = null);
 
 public sealed record TaskDto(
     string Id,
@@ -49,6 +50,9 @@ public sealed record TaskDto(
 
 // Lean counterpart to TaskDto for writing/status-changing tools: echoes back what changed
 // without re-sending Description/Result, which the caller just sent or already has.
+// BaseDirty is populated only where the task just transitioned to Queued (or ran immediately
+// via run_task_now) and its list's working directory has uncommitted changes -- see
+// ClaudeDo.Worker.Git.BaseDirtyChecker. Every other caller leaves it null.
 public sealed record TaskRefDto(
     string Id,
     string ListId,
@@ -56,7 +60,8 @@ public sealed record TaskRefDto(
     string Status,
     int SortOrder,
     bool IsMyDay,
-    int RoadblockCount = 0);
+    int RoadblockCount = 0,
+    DirtyBaseWarning? BaseDirty = null);
 
 // tasks is populated when includeDescription=false (the default): lean references, no
 // Description/Result. tasksFull is populated when includeDescription=true: full tasks incl.
@@ -135,6 +140,7 @@ public sealed class ExternalMcpService
     private readonly WorktreeMaintenanceService _maintenance;
     private readonly TaskMergeService _merge;
     private readonly PlanningMergeOrchestrator _planningMerge;
+    private readonly IBaseDirtyChecker _baseDirtyChecker;
 
     public ExternalMcpService(
         TaskRepository tasks,
@@ -146,7 +152,8 @@ public sealed class ExternalMcpService
         IDbContextFactory<ClaudeDoDbContext> dbFactory,
         WorktreeMaintenanceService maintenance,
         TaskMergeService merge,
-        PlanningMergeOrchestrator planningMerge)
+        PlanningMergeOrchestrator planningMerge,
+        IBaseDirtyChecker baseDirtyChecker)
     {
         _tasks = tasks;
         _lists = lists;
@@ -158,6 +165,7 @@ public sealed class ExternalMcpService
         _maintenance = maintenance;
         _merge = merge;
         _planningMerge = planningMerge;
+        _baseDirtyChecker = baseDirtyChecker;
     }
 
     [McpServerTool, Description(
@@ -436,6 +444,7 @@ public sealed class ExternalMcpService
         var task = await _tasks.GetByIdAsync(taskId, cancellationToken)
             ?? throw new InvalidOperationException($"Task {taskId} not found.");
 
+        DirtyBaseWarning? baseDirty = null;
         switch (target)
         {
             case TaskStatus.Idle:
@@ -447,6 +456,7 @@ public sealed class ExternalMcpService
                 var enqueueResult = await _state.EnqueueAsync(taskId, cancellationToken);
                 if (!enqueueResult.Ok)
                     throw new InvalidOperationException(enqueueResult.Reason ?? "Cannot enqueue task.");
+                baseDirty = enqueueResult.BaseDirty;
                 break;
 
             case TaskStatus.Cancelled:
@@ -475,7 +485,7 @@ public sealed class ExternalMcpService
         }
 
         var reload = (await _tasks.GetByIdAsync(taskId, cancellationToken))!;
-        return ToRefDto(reload);
+        return ToRefDto(reload) with { BaseDirty = baseDirty };
     }
 
     [McpServerTool, Description(
@@ -652,7 +662,15 @@ public sealed class ExternalMcpService
             throw new InvalidOperationException($"Task {taskId} not found.");
         }
         await _broadcaster.TaskUpdated(taskId);
-        return new RunTaskNowResult(true, taskId);
+
+        // Heads-up only, same as update_task_status's Queued path: a worktree forks from the
+        // commit tip, not the working tree, so uncommitted changes in the list's repo right now
+        // won't be included.
+        var task = await _tasks.GetByIdAsync(taskId, cancellationToken);
+        var list = task is not null ? await _lists.GetByIdAsync(task.ListId, cancellationToken) : null;
+        var baseDirty = await _baseDirtyChecker.CheckAsync(list?.WorkingDir, cancellationToken);
+
+        return new RunTaskNowResult(true, taskId, baseDirty);
     }
 
     [McpServerTool, Description(