Cleans and normalizes WhatsApp phone numbers by:
Skipping normalization if the entry already contains a JID suffix (e.g., "@s.whatsapp.net" or "@g.us");
Otherwise, removing all non-digit characters (+, spaces, parentheses, hyphens, etc.);
Removing the ninth digit (when present) right after the country code (CC) and area code (SS), in order to standardize to 12 or 13 digits.
whapi_normalize_to(to)A character vector of normalized IDs (phones -> digits only, JIDs kept as-is).
Character. A character vector of WhatsApp numbers in free text format or JIDs.
This function is primarily designed for Brazilian E.164 numbers (e.g.,
+55 (81) 9XXXX-YYYY).