Don't add '.' if prompt already ends with punctuation (.!?,;:). Logic: endsWithPunct || startsLower = just space, otherwise '. ' Prevents double-period '..' on continuation join.
Don't add '.' if prompt already ends with punctuation (.!?,;:). Logic: endsWithPunct || startsLower = just space, otherwise '. ' Prevents double-period '..' on continuation join.