fix(dev): add Docker volume path mapping to testing-host for database deployments

Database deployments generate bind mounts referencing the internal Docker
volume path (/var/lib/docker/volumes/coolify_dev_coolify_data/_data) which
doesn't exist in the testing-host container. This adds the missing volume
mount so both /data/coolify and the Docker volume path resolve correctly.

Fixes #9533

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

docker-compose.dev.yml

@@ -112,6 +112,7 @@ services:
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock
       - dev_coolify_data:/data/coolify
+      - dev_coolify_data:/var/lib/docker/volumes/coolify_dev_coolify_data/_data
       - dev_backups_data:/data/coolify/backups
       - dev_postgres_data:/data/coolify/_volumes/database
       - dev_redis_data:/data/coolify/_volumes/redis