chore: consolidate all persistent data into ./data folder

- Update docker-compose.yml to mount Caddyfile from ./data
- Remove Dockerfile directory creation - handled by init-data.sh
- Add init-data.sh script to initialize ./data with all required files
- Add DATA_DEPLOYMENT.md documentation for deployment workflow
- Update .gitignore to exclude ./data folder
- All persistent data (app, config, database, uploads) now centralized in ./data

docker-compose.yml

@@ -8,9 +8,9 @@ services:
     expose:
       - "5000"
     volumes:
-      - ./instance:/app/instance
-      - ./app/static/uploads:/app/app/static/uploads
-      - ./Caddyfile:/app/Caddyfile
+      - ./data/app:/app
+      - ./data/instance:/app/instance
+      - ./data/uploads:/app/app/static/uploads
     environment:
       - FLASK_ENV=production
       - SECRET_KEY=${SECRET_KEY:-your-secret-key-change-this}
@@ -36,9 +36,9 @@ services:
       - "443:443/udp"  # HTTP/3 support
       - "2019:2019"     # Caddy admin API
     volumes:
-      - ./Caddyfile:/etc/caddy/Caddyfile:ro
-      - caddy-data:/data
-      - caddy-config:/config
+      - ./data/Caddyfile:/etc/caddy/Caddyfile:ro
+      - ./data/caddy-data:/data
+      - ./data/caddy-config:/config
     environment:
       - DOMAIN=${DOMAIN:-localhost}
       - EMAIL=${EMAIL:-admin@localhost}
@@ -52,7 +52,3 @@ services:
 networks:
   digiserver-network:
     driver: bridge
-
-volumes:
-  caddy-data:
-  caddy-config: