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.Ui/Services/Interfaces/IWorkerClient.cs

@@ -75,7 +75,10 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task<List<string>> InstallSessionSkillAsync(string url);
     Task UpdateSessionSkillAsync(string sourceUrl);
     Task RemoveSessionSkillAsync(string sourceUrl);
-    Task SetTaskStatusAsync(string taskId, TaskStatus status);
+    /// <summary>Returns the base-dirty heads-up when this transition just queued the task against
+    /// a list whose working dir has uncommitted changes (null otherwise) — a new worktree forks
+    /// from the last commit, not the working tree, so those changes won't be included.</summary>
+    Task<BaseDirtyWarningDto?> SetTaskStatusAsync(string taskId, TaskStatus status);
     Task<MergeResultDto?> ApproveReviewAsync(string taskId, string targetBranch);
     Task<MergePreviewDto?> PreviewMergeAsync(string taskId, string targetBranch);
     Task<MergeResultDto> MergeTaskAsync(string taskId, string targetBranch, bool removeWorktree, string commitMessage);

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -483,9 +483,10 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public Task RemoveSessionSkillAsync(string sourceUrl)
         => _hub.InvokeAsync("RemoveSessionSkill", sourceUrl);
 
-    public async Task SetTaskStatusAsync(string taskId, ClaudeDo.Data.Models.TaskStatus status)
+    public async Task<BaseDirtyWarningDto?> SetTaskStatusAsync(string taskId, ClaudeDo.Data.Models.TaskStatus status)
     {
-        await _hub.InvokeAsync("SetTaskStatus", taskId, status.ToString());
+        var result = await _hub.InvokeAsync<SetTaskStatusResultDto>("SetTaskStatus", taskId, status.ToString());
+        return result?.BaseDirty;
     }
 
     public async Task<MergeResultDto?> ApproveReviewAsync(string taskId, string targetBranch)
@@ -690,6 +691,8 @@ public sealed record SessionSkillDto(
 public sealed record WorktreeCleanupDto(int Removed);
 public sealed record WorktreeResetDto(int Removed, int TasksAffected, bool Blocked, int RunningTasks);
 public record MergeResultDto(string Status, IReadOnlyList<string> ConflictFiles, string? ErrorMessage);
+public record BaseDirtyWarningDto(int ModifiedCount, int UntrackedCount);
+public record SetTaskStatusResultDto(BaseDirtyWarningDto? BaseDirty);
 public record MergePreviewDto(string Status, IReadOnlyList<string> ConflictFiles, int ChangedFileCount);
 public record MergeTargetsDto(string DefaultBranch, IReadOnlyList<string> LocalBranches);
 public record MergeConflictDocumentsDto(string TaskId, IReadOnlyList<ConflictDocumentDto> Files);