add: custom postgress data path for coolify docker compose

COOLIFY_DEPLOYMENT.md

@@ -27,7 +27,12 @@ Choose one:
    - Build Pack: Docker Compose
    - File: `./docker-compose.coolify.yml`
 4. Assign domain to `app` service only (format: `http://yourdomain.com:3000`)
-5. Set environment variables (if needed)
+5. Set environment variables:
+   - `AUTH_SECRET` (generate with `openssl rand -base64 32`)
+   - `AUTH_URL` (your domain with https)
+   - `POSTGRES_DATA_PATH` (optional, for custom database storage location)
+   - `GOOGLE_CLIENT_ID` (optional)
+   - `GOOGLE_CLIENT_SECRET` (optional)
 6. Deploy
 
 ### Using Dockerfile
@@ -65,6 +70,10 @@ Required:
 Optional:
 - `GOOGLE_CLIENT_ID`
 - `GOOGLE_CLIENT_SECRET`
+- `POSTGRES_DATA_PATH` - Custom path for PostgreSQL data (Docker Compose only)
+  - Example: `/mnt/storage/wishlist/postgres`
+  - If not set, uses a Docker named volume
+  - Path must exist with proper permissions before deployment
 
 ## Troubleshooting