Check whether phone numbers or usernames belong to Telegram accounts

These helpers port the functionality of bellingcat's telegram-phone-number-checker Python tool to R. They use the currently authenticated [TelegramClient] to look up users by phone number (via `ImportContactsRequest` / `DeleteContactsRequest`) or by username (via `client$get_entity()`), and return the public profile fields Telegram returns about the matched user.

Details

Phone-number lookups briefly add the number to your contact list and then delete it. Telegram throttles abusive callers — Bellingcat recommends using a fresh, residential-IP account rather than a personal one.