implement .env configuration support and restrict web interface to localhost

docker-compose.yml

@@ -5,11 +5,11 @@ services:
     build: .
     container_name: xivlauncher-remote-otp
     ports:
-      - "8080:8080"
+      - "127.0.0.1:8080:8080"
     volumes:
       - ./data:/app/data
     environment:
-      - WEB_PASSWORD=admin
+      - WEB_PASSWORD=${WEB_PASSWORD:-admin}
       # Generate a secure key using: python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"
-      - ENCRYPTION_KEY=CHANGE_ME_TO_A_VALID_FERNET_KEY
+      - ENCRYPTION_KEY=${ENCRYPTION_KEY:-CHANGE_ME_TO_A_VALID_FERNET_KEY}
     restart: unless-stopped