?? Heartbeat API Instructions
-----------------------------
1. Send a POST request with JSON body:
   {
     "bot_id": "BOT123",
     "status": "ok"
   }

2. Table structure (MySQL):
   CREATE TABLE bots (
     id INT AUTO_INCREMENT PRIMARY KEY,
     bot_id VARCHAR(100) UNIQUE NOT NULL,
     last_seen DATETIME NOT NULL,
     status VARCHAR(50)
   );

3. Example with curl:
   curl -X POST -H "Content-Type: application/json" \
   -d '{\"bot_id\":\"BOT123\",\"status\":\"ok\"}' \
   http://yourserver/heartbeat.php