feat: generate secure secret key and prevent default

docker-compose.testing.yml

@@ -49,6 +49,7 @@ services:
       - GOOGLE_CLIENT_SECRET=${GOOGLE_CLIENT_SECRET}
       - GITHUB_CLIENT_ID=${GITHUB_CLIENT_ID}
       - GITHUB_CLIENT_SECRET=${GITHUB_CLIENT_SECRET}
+      - SECRET_KEY=${SECRET_KEY}
 
   db-test:
     image: mongo