Actually truly really NOW actually for real truly now fix docker compose in updater

updater/Dockerfile

@@ -20,7 +20,11 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/*
 
 # Add user to the docker group
-RUN usermod -aG docker www-data
+RUN usermod -aG $DOCKER_GID www-data
+
+# Create .docker directory and set permissions
+RUN mkdir -p /var/www/.docker && \
+    chown www-data:www-data /var/www/.docker
 
 # Copy the PHP file to the Apache document root
 COPY webhook.php /var/www/html/index.php