Watches IMAP folders for new messages. When a new message is added to INBOX or Screened Out the sender is added/updated in a CardDAV address book and contact groups are adjusted:

• If message lands in INBOX: ensure contact exists, remove Screened Out group, add Screened group
• If message lands in Screened Out: ensure contact exists, remove Screened group, add Screened Out group

Setup:

1. Copy .env.example to .env and fill in values.
2. npm install
3. npm start

Notes:

• This project uses the imap package to watch folders. Some IMAP servers support IDLE; others require polling.
• CardDAV operations are performed via WebDAV requests using node-fetch.