Update Coolify deployment guide to clarify production and development dependencies; refactor import statements for consistency and add requirements-dev.txt for development dependencies.

Co-authored-by: Copilot <copilot@github.com>

frontend/app/main.py

@@ -13,7 +13,7 @@ from flask import (
     url_for,
 )
 
-from frontend.app.config import Config
+from .config import Config
 
 app = Flask(__name__)
 app.config.from_object(Config)