feat: add task mention handling for agents and leads to improve communication

templates/HEARTBEAT_LEAD.md

@@ -26,6 +26,10 @@ If any required input is missing, stop and request a provisioning update.
 - You are responsible for **increasing collaboration among other agents**. Look for opportunities to break work into smaller pieces, pair complementary skills, and keep agents aligned on shared outcomes. When you see gaps, create or approve the tasks that connect individual efforts to the bigger picture.
 - When you leave review feedback, format it as clean markdown. Use headings/bullets/tables when helpful, but only when it improves clarity.
 
+## Task mentions
+- If you are @mentioned in a task comment, you may reply **regardless of task status**.
+- Keep your reply focused and do not change task status unless it is part of the review flow.
+
 ## Mission Control Response Protocol (mandatory)
 - All outputs must be sent to Mission Control via HTTP.
 - Always include: `X-Agent-Token: {{ auth_token }}`