feat(worker): AskUser MCP tool so a running task can ask the user mid-run

A running task can call mcp__claudedo_run__AskUser(question) to block (up to 3
min) on a human answer. PendingQuestionRegistry holds the pending question +
TaskCompletionSource; the tool broadcasts TaskQuestionAsked, awaits the answer
(WorkerHub.AnswerTaskQuestion resolves it), and returns it as the tool result —
or a 'proceed on your judgment' fallback on timeout. The run stays Running
throughout (no status/schema change). ClaudeProcess raises MCP_TOOL_TIMEOUT so
the 60s HTTP-MCP cap doesn't kill the wait; the run MCP is now wired for every
task, not just standalone ones. System prompt updated to reconcile 'unattended'.

src/ClaudeDo.Worker/Hub/HubBroadcaster.cs

@@ -26,6 +26,12 @@ public sealed class HubBroadcaster : IPrimeBroadcaster, IRefineBroadcaster
     public Task TaskUpdated(string taskId) =>
         _hub.Clients.All.SendAsync("TaskUpdated", taskId);
 
+    public Task TaskQuestionAsked(string taskId, string questionId, string question) =>
+        _hub.Clients.All.SendAsync("TaskQuestionAsked", taskId, questionId, question);
+
+    public Task TaskQuestionResolved(string taskId, string questionId) =>
+        _hub.Clients.All.SendAsync("TaskQuestionResolved", taskId, questionId);
+
     public Task ListUpdated(string listId) =>
         _hub.Clients.All.SendAsync("ListUpdated", listId);
 

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -56,6 +56,7 @@ public record WorktreeOverviewDto(
     bool PathExistsOnDisk);
 
 public record ForceRemoveResultDto(bool Removed, string? Reason);
+public record PendingQuestionDto(string TaskId, string QuestionId, string Question);
 public record MergeResultDto(string Status, IReadOnlyList<string> ConflictFiles, string? ErrorMessage);
 public record MergePreviewDto(string Status, IReadOnlyList<string> ConflictFiles, int ChangedFileCount);
 public record MergeTargetsDto(string DefaultBranch, IReadOnlyList<string> LocalBranches);
@@ -114,6 +115,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     private readonly WorkerConfig _cfg;
     private readonly OnlineInboxConfig _onlineInboxConfig;
     private readonly OnlineTokenStore _onlineTokenStore;
+    private readonly Runner.PendingQuestionRegistry _pendingQuestions;
     private readonly LogRingBuffer? _logBuffer;
 
     public WorkerHub(
@@ -139,6 +141,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         WorkerConfig cfg,
         OnlineInboxConfig onlineInboxConfig,
         OnlineTokenStore onlineTokenStore,
+        Runner.PendingQuestionRegistry pendingQuestions,
         LogRingBuffer? logBuffer = null)
     {
         _queue = queue;
@@ -163,9 +166,22 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         _cfg = cfg;
         _onlineInboxConfig = onlineInboxConfig;
         _onlineTokenStore = onlineTokenStore;
+        _pendingQuestions = pendingQuestions;
         _logBuffer = logBuffer;
     }
 
+    /// <summary>Deliver the user's answer to a question a running task raised via AskUser.
+    /// Returns false if no matching question is still pending (already answered or timed out).</summary>
+    public bool AnswerTaskQuestion(string taskId, string questionId, string answer) =>
+        _pendingQuestions.TryAnswer(taskId, questionId, answer ?? string.Empty);
+
+    /// <summary>The question a running task is currently blocked on, if any (for UI re-attach).</summary>
+    public PendingQuestionDto? GetPendingQuestion(string taskId)
+    {
+        var q = _pendingQuestions.Get(taskId);
+        return q is null ? null : new PendingQuestionDto(q.TaskId, q.QuestionId, q.Question);
+    }
+
     /// <summary>Recent worker log records (last 30 min, all levels) for the Log Visualizer overlay.</summary>
     public IReadOnlyList<WorkerLogRecord> GetRecentLogs() =>
         _logBuffer?.Snapshot() ?? Array.Empty<WorkerLogRecord>();