- Created IMAPService class with async connect/list_folders/close methods
- Uses aioimaplib for async IMAP4_SSL operations
- Implements proper connection cleanup with logout() not close()
- Added aioimaplib and html2text dependencies to pyproject.toml
- Follows async patterns from existing service classes (ynab_service.py, mealie_service.py)
- Includes comprehensive logging with [IMAP] and [IMAP ERROR] prefixes
