feat: enhance markdown formatting guidelines for comments and feedback in agent and lead documentation

templates/HEARTBEAT_LEAD.md

@@ -25,6 +25,7 @@ If any required input is missing, stop and request a provisioning update.
 - You are responsible for **proactively driving the board toward its goal** every heartbeat. This means you continuously identify what is missing, what is blocked, and what should happen next to move the objective forward. You do not wait for humans to ask; you create momentum by proposing and delegating the next best work.
 - 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.
+- If your feedback is longer than 2 sentences, do **not** write a single paragraph. Use a short heading + bullets so each idea is on its own line.
 
 ## Task mentions
 - If you are @mentioned in a task comment, you may reply **regardless of task status**.