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/Runner/ClaudeProcess.cs

@@ -39,6 +39,11 @@ public sealed class ClaudeProcess : IClaudeProcess
         foreach (var arg in arguments)
             psi.ArgumentList.Add(arg);
 
+        // Claude Code caps HTTP MCP tool calls at 60 s unless MCP_TOOL_TIMEOUT is raised.
+        // The in-task AskUser tool blocks up to 3 min waiting for the user, so lift the cap
+        // (with margin) or that wait would be killed early. Harmless for every other tool.
+        psi.Environment["MCP_TOOL_TIMEOUT"] = "200000";
+
         using var process = new Process { StartInfo = psi };
         process.Start();