The helper renders French period labels (Janvier 2026, T2 2026, S1 2026),
so it carries the fr prefix like frDate. Config example, arch.md and
user-stories.md updated. Configs calling period(...) must switch to
frPeriod(...).
Go date layouts only know English month names, so date(value, layout)
cannot parse "le 19 janvier 2026". frDate(text) extracts and parses such
dates (day optional, abbreviated months, accents optional) into a native
date; no match is a rule error routing the document to pending/.
Documented in arch.md §5, covered by unit tests.
thomas