feat: add python-dotenv dependency for .env file support

- Add python-dotenv>=0.19.0 to project dependencies
- Enable automatic loading of environment variables from .env files
- Support development and production environment configuration

pyproject.toml

@@ -36,6 +36,7 @@ dependencies = [
     "pydantic>=1.8.0,<2.0.0",
     "jinja2>=3.0.0,<4.0.0",
     "python-multipart>=0.0.5",
+    "python-dotenv>=0.19.0",
     "pyyaml>=5.4.0",
     "validators>=0.18.0",
 ]