Refactor configuration and security features for improved development experience

- Updated the .env.example file to reflect a development environment setup with enhanced secret key requirements and local host settings.
- Modified the Docker Compose configuration to enhance security with read-only settings and no-new-privileges options.
- Updated requirements.txt to pin package versions for better dependency management.
- Enhanced the FastAPI application to include dynamic OpenAPI and documentation URLs based on the environment.
- Implemented session versioning in JWT tokens to improve security and user session management.
- Added new validation for user roles and password strength in schemas.
- Improved email sending logic to handle recipient lists more robustly and added logging for SMTP operations.
- Updated dashboard and profile templates to reflect new features and improve user experience.

docker-compose.yml

@@ -9,6 +9,11 @@ services:
     volumes:
       - newsletter_data:/app/data
     restart: unless-stopped
+    security_opt:
+      - no-new-privileges:true
+    read_only: true
+    tmpfs:
+      - /tmp
     healthcheck:
       test: ["CMD-SHELL", "python -c \"import urllib.request; urllib.request.urlopen('http://localhost:8000/login').read()\""]
       interval: 30s