fix: pin watchtower 1.7.1 + set DOCKER_API_VERSION=1.40 for compatibility

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tanviet12

docker-compose.hub.yml

@@ -73,7 +73,7 @@ services:
       --default-authentication-plugin=mysql_native_password
 
   watchtower:
-    image: containrrr/watchtower
+    image: containrrr/watchtower:1.7.1
     container_name: cqa-watchtower
     restart: unless-stopped
     volumes:
@@ -82,6 +82,7 @@ services:
       - WATCHTOWER_CLEANUP=true
       - WATCHTOWER_POLL_INTERVAL=300
       - WATCHTOWER_LABEL_ENABLE=true
+      - DOCKER_API_VERSION=1.40
 
 volumes:
   mysql_data: