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/Program.cs

@@ -6,6 +6,7 @@ using ClaudeDo.Worker.Agents;
 using ClaudeDo.Worker.Config;
 using ClaudeDo.Worker.External;
 using ClaudeDo.Worker.Findings;
+using ClaudeDo.Worker.Git;
 using ClaudeDo.Worker.Hub;
 using ClaudeDo.Worker.Lifecycle;
 using ClaudeDo.Worker.Logging;
@@ -107,6 +108,7 @@ builder.Services.AddSingleton<Func<ITaskStateService>>(sp => () => sp.GetRequire
 // PlanningMergeOrchestrator itself depends on ITaskStateService, so TaskStateService can only
 // reach it lazily (Func<IActiveMergeState>) — same cycle-breaking shape as the Func above.
 builder.Services.AddSingleton<Func<IActiveMergeState>>(sp => () => sp.GetRequiredService<PlanningMergeOrchestrator>());
+builder.Services.AddSingleton<IBaseDirtyChecker, BaseDirtyChecker>();
 builder.Services.AddSingleton<ITaskStateService>(sp => new TaskStateService(
     sp.GetRequiredService<IDbContextFactory<ClaudeDoDbContext>>(),
     sp.GetRequiredService<HubBroadcaster>(),
@@ -114,6 +116,7 @@ builder.Services.AddSingleton<ITaskStateService>(sp => new TaskStateService(
     sp.GetRequiredService<PlanningChainCoordinator>(),
     sp.GetRequiredService<RunCancellationRegistry>(),
     sp.GetRequiredService<Func<IActiveMergeState>>(),
+    sp.GetRequiredService<IBaseDirtyChecker>(),
     sp.GetRequiredService<ILogger<TaskStateService>>()));
 
 // Agent file management.
@@ -302,6 +305,7 @@ if (cfg.ExternalMcpPort > 0)
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<AgentFileService>());
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<TaskResetService>());
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<GitService>());
+    externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<IBaseDirtyChecker>());
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<WorktreeMaintenanceService>());
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<TaskMergeService>());
     externalBuilder.Services.AddSingleton(app.Services.GetRequiredService<PlanningMergeOrchestrator>());