docs(code): add concise docstrings

src/gapido_auth/infrastructure/worker.py

@@ -27,6 +27,8 @@ async def handle_message(
     exchange: Any,
     dlx: Any,
 ) -> None:
+    """Process one SMS job, retry bounded failures, and dead-letter permanent failures."""
+
     async with message.process(ignore_processed=True, requeue=False):
         payload = json.loads(message.body.decode())
         job = SmsJob(**payload)
@@ -48,6 +50,7 @@ async def handle_message(
                 )
                 return
 
+            # Re-publish instead of requeueing indefinitely so retries remain bounded.
             logger.warning(
                 "SMS job failed for mobile=%s retry=%s", job.mobile, retry_count + 1, exc_info=True
             )
@@ -63,6 +66,8 @@ async def handle_message(
 
 
 async def main() -> None:
+    """Start the RabbitMQ consumer and bind it to the configured SMS strategy."""
+
     logging.basicConfig(level=logging.INFO)
     settings = get_settings()
     connection = await connect_robust(settings.rabbitmq_url)