feat: split heartbeat templates and allow lead agent creation

templates/HEARTBEAT.md

@@ -1,7 +1,9 @@
 # HEARTBEAT.md
 
+> This file is provisioned from HEARTBEAT_LEAD.md or HEARTBEAT_AGENT.md. If you see this template directly, follow the agent loop below.
+
 ## Purpose
-This file defines the single, authoritative heartbeat loop. Follow it exactly.
+This file defines the single, authoritative heartbeat loop for non-lead agents. Follow it exactly.
 
 ## Required inputs
 - BASE_URL (e.g. http://localhost:8000)
@@ -30,26 +32,6 @@ If any required input is missing, stop and request a provisioning update.
   - GET $BASE_URL/api/v1/boards/{BOARD_ID}/tasks must succeed.
 - If any check fails, stop and retry next heartbeat.
 
-## Board Lead Loop (if IS_BOARD_LEAD == true)
-When you are the board lead, run this loop after pre-flight checks and before claiming work:
-1) Read board goal context:
-   - Board: {{ board_name }} ({{ board_type }})
-   - Objective: {{ board_objective }}
-   - Success metrics: {{ board_success_metrics }}
-   - Target date: {{ board_target_date }}
-2) Review recent tasks/comments and board memory:
-   - GET $BASE_URL/api/v1/boards/{BOARD_ID}/tasks?limit=50
-   - GET $BASE_URL/api/v1/boards/{BOARD_ID}/memory?limit=50
-3) Update a short Board Plan Summary in board memory:
-   - POST $BASE_URL/api/v1/boards/{BOARD_ID}/memory
-     Body: {"content":"Plan summary + next gaps","tags":["plan","lead"],"source":"lead_heartbeat"}
-4) Identify missing steps and propose tasks.
-5) For each candidate task, compute confidence (rubric) and check risk/external actions:
-   - If risky/external or confidence < 80, create an approval:
-     - POST $BASE_URL/api/v1/boards/{BOARD_ID}/approvals
-   - Else create the task and assign an agent.
-6) Post a brief status update in board memory (1-3 bullets).
-
 ## Heartbeat checklist (run in order)
 1) Check in:
 ```bash