refactor: Use Docker Compose managed volume with project prefix

Changes:
- docker-compose.yml: Change from external volume to managed volume
  - Volume name: nlcc-data → data
  - Docker Compose auto-prefixes: nlcc-itinerary_data
  - Remove external: true flag
  - Volume created automatically on first up

- README.md: Update all volume references
  - Installation: Remove manual volume creation step
  - Volume name: nlcc-data → nlcc-itinerary_data
  - Add note about automatic creation
  - Update all backup/restore/inspect commands

Benefits:
- No manual volume creation required
- Docker Compose manages lifecycle automatically
- Project-scoped volume naming (nlcc-itinerary_data)
- Cleaner deployment process (one less step)
- Volume automatically created on docker-compose up
- Consistent with Docker Compose best practices

The volume will be created as "nlcc-itinerary_data" where:
- nlcc-itinerary = project directory name
- data = volume name defined in docker-compose.yml

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -87,16 +87,13 @@ cd nlcc-itinerary
    - Configure email settings (required for password resets)
    - Optionally set `ADMIN_USERNAME` and `ADMIN_PASSWORD` (otherwise auto-generated)
 
-3. Create the external Docker volume for data persistence:
-```bash
-docker volume create nlcc-data
-```
-
-4. Build and run with Docker Compose:
+3. Build and run with Docker Compose:
 ```bash
 docker-compose up -d --build
 ```
 
+The Docker volume will be automatically created as `nlcc-itinerary_data`.
+
 The application will be available at `http://localhost:3002` (or your configured port)
 
 **Important**: The `SITE_URL` must be set correctly for QR codes to work. This should be the public URL where your application is accessible (e.g., `https://church.example.com`).
@@ -315,28 +312,26 @@ docker exec -it nlcc-itinerary sh
 
 ## Data Persistence
 
-The SQLite database is stored in a Docker named volume (`nlcc-data`) which is mounted to `/app/data` in the container. This ensures:
+The SQLite database is stored in a Docker named volume (`nlcc-itinerary_data`) which is mounted to `/app/data` in the container. This ensures:
 - Data persists across container restarts and rebuilds
 - Better portability across different environments
 - Easier backup and restore operations
 - Managed by Docker volume system
+- Automatic creation on first `docker-compose up`
 
 **Volume Management Commands**:
 ```bash
-# Create the volume (required before first run)
-docker volume create nlcc-data
-
 # Inspect volume location and details
-docker volume inspect nlcc-data
+docker volume inspect nlcc-itinerary_data
 
 # Backup the database
-docker run --rm -v nlcc-data:/data -v $(pwd):/backup alpine tar czf /backup/nlcc-backup.tar.gz -C /data .
+docker run --rm -v nlcc-itinerary_data:/data -v $(pwd):/backup alpine tar czf /backup/nlcc-backup.tar.gz -C /data .
 
 # Restore from backup
-docker run --rm -v nlcc-data:/data -v $(pwd):/backup alpine tar xzf /backup/nlcc-backup.tar.gz -C /data
+docker run --rm -v nlcc-itinerary_data:/data -v $(pwd):/backup alpine tar xzf /backup/nlcc-backup.tar.gz -C /data
 
 # Remove volume (WARNING: deletes all data!)
-docker volume rm nlcc-data
+docker volume rm nlcc-itinerary_data
 ```
 
 ## License

docker-compose.yml

@@ -5,7 +5,7 @@ services:
     ports:
       - "3002:3000"
     volumes:
-      - nlcc-data:/app/data
+      - data:/app/data
     environment:
       - NODE_ENV=production
       - SITE_URL=https://church.example.com
@@ -22,5 +22,4 @@ services:
     restart: unless-stopped
 
 volumes:
-  nlcc-data:
-    external: true
+  data: