chore: upgrade n8n to 2.34.2 + postgres autoupgrade

- bump image n8nio/n8n:2.1.4 -> 2.34.2
- switch postgres image to pgautoupgrade/pgautoupgrade:18-alpine
- adjust postgres volume mount path for pgautoupgrade
- version label bump deferred to 'abra recipe release'

compose.postgres.yml

@@ -14,7 +14,7 @@ services:
       - db_password
 
   db:
-    image: postgres:16
+    image: pgautoupgrade/pgautoupgrade:18-alpine
     networks:
       - internal_network
     environment:
@@ -30,7 +30,7 @@ services:
     healthcheck:
       test: ["CMD", "pg_isready", "-U", "root", "-d", "n8n"]
     volumes:
-      - 'postgresql_data:/var/lib/postgresql/data'
+      - 'postgresql_data:/var/lib/postgresql'
     entrypoint: /docker-entrypoint.sh
     deploy:
       labels: