Full-width numbers are always treated as Hangul

This can lead to situations where text that is dominated by numbers (e.g. dates) is interpreted as Hangul and Korean, despite not having a single true Hangul character. I tested with today's date in Japanese/Mandarin (they're written the same), `２０２５年１０月１７日`. If I replace the full-width numbers with regular numbers (`2025年10月17日`), the expected result of Mandarin is returned.