feat: implement ORCID OAuth callback and update environment configuration

- Added ORCID_REDIRECT_URI to docker-compose for OAuth integration.
- Introduced a new callback endpoint to handle ORCID login and token exchange.
- Refactored authentication logic to streamline the OAuth process.
- Ensured local environment variables are loaded for development.

docker-compose.yml

@@ -11,6 +11,7 @@ services:
     environment:
       DATABASE_URL: postgresql://postgres:postgres@db:5432/orcid_db
       REDIS_URL: redis://redis:6379/0
+      ORCID_REDIRECT_URI: https://willfully-brunette-antennae.ngrok-free.dev/callback
     depends_on:
       - db
       - redis