fix(heartbeat): replace HEARTBEAT_OK token with virtual tool-call decision

nanobot/cli/commands.py

@@ -360,19 +360,19 @@ def gateway(
         return "cli", "direct"
 
     # Create heartbeat service
-    async def on_heartbeat(prompt: str) -> str:
-        """Execute heartbeat through the agent."""
+    async def on_heartbeat_execute(tasks: str) -> str:
+        """Phase 2: execute heartbeat tasks through the full agent loop."""
         channel, chat_id = _pick_heartbeat_target()
 
         async def _silent(*_args, **_kwargs):
             pass
 
         return await agent.process_direct(
-            prompt,
+            tasks,
             session_key="heartbeat",
             channel=channel,
             chat_id=chat_id,
-            on_progress=_silent,  # suppress: heartbeat should not push progress to external channels
+            on_progress=_silent,
         )
 
     async def on_heartbeat_notify(response: str) -> None:
@@ -383,12 +383,15 @@ def gateway(
             return  # No external channel available to deliver to
         await bus.publish_outbound(OutboundMessage(channel=channel, chat_id=chat_id, content=response))
 
+    hb_cfg = config.gateway.heartbeat
     heartbeat = HeartbeatService(
         workspace=config.workspace_path,
-        on_heartbeat=on_heartbeat,
+        provider=provider,
+        model=agent.model,
+        on_execute=on_heartbeat_execute,
         on_notify=on_heartbeat_notify,
-        interval_s=30 * 60,  # 30 minutes
-        enabled=True
+        interval_s=hb_cfg.interval_s,
+        enabled=hb_cfg.enabled,
     )
     
     if channels.enabled_channels: