ReadonlybriefThe full text of analysis/daily/$DATE/$SUB/executive-brief_<lang>.md. The caller is responsible for reading it from disk. Pass null / empty string when the file does not exist — the function returns { title: null, description: null } in that case so the caller can cleanly fall through to the next cascade layer.
ReadonlysubfolderThe analysis subfolder slug (e.g. propositions, interpellations, weekly-review). Used by cleanArticleTitle to reject H1s that collapse to the subfolder fallback (boilerplate category labels).
Optional ReadonlylangOptional BCP-47 / file-suffix language code (e.g. de, ar, ja). When supplied, the description is truncated using the per-language SERP window from descriptionWindowForLanguage — 140-200 for Latin LTR, 120-170 for RTL (ar/he), 70-120 for CJK (ja/ko/zh). When omitted, falls back to the canonical EN 140-200 window (preserves pre-2026-05 behaviour for callers that have not yet been updated).
Input contract for extractLocalizedBriefSeo. The brief markdown is the full file contents of
executive-brief_<lang>.md(front-matter# Propositionsis rejected when the subfolder ispropositions).