Implement data persistence for safe app updates

- Add external volume mounting for database, uploads, and media files
- Update Dockerfile to conditionally initialize database only if it doesn't exist
- Move database to external /data volume for persistence across rebuilds
- Configure production environment with proper FLASK_CONFIG
- Add volume mappings for complete data persistence:
  * ./data:/data - Database persistence
  * ./uploads:/opt/moto_site/uploads - File uploads persistence
  * ./static/media:/opt/moto_site/static/media - Media files persistence
- Create init script that skips database creation if DB already exists
- Enable safe app updates without losing users, posts, or tracks

This ensures all user data persists across Docker container rebuilds and app updates.

docker-compose.yml

@@ -8,10 +8,12 @@ services:
     ports:
       - "8100:5000"
     environment:
-      - FLASK_ENV=production
-      - DATABASE_URL=sqlite:///moto_adventure.db
+      - FLASK_CONFIG=production
+      - DATABASE_URL=sqlite:////data/moto_adventure.db
       - SECRET_KEY=ana_are_mere_si-si-pere_cat-cuprinde_in_cos
     working_dir: /opt/moto_site
     volumes:
-      - ./uploads:/opt/moto_site/uploads
+      - ./data:/data  # Database persistence
+      - ./uploads:/opt/moto_site/uploads  # File uploads persistence
+      - ./static/media:/opt/moto_site/static/media  # Media files persistence
     restart: unless-stopped