CH table metadata: omie.unavailabilities

# `omie.unavailabilities` Per-unit unavailability declarations OMIE receives directly from agents (`indisp`=España, `indisppt`=Portugal — same file family under Mercado Diario/Intradiario/Continuo, "N. Indisponibilidades"). Unlike esios.unavailability_events (I90 DIA16, REE side, D-90), these declarations are published same-day and often cover future delivery windows — the only per-unit availability signal on the OMIE side without the I90/T+90 lag. Each source file is a full snapshot of the currently active register as of its own publication timestamp, republished whenever a declaration is filed, amended or withdrawn (not one file per calendar day — most days have none). ReplacingMergeTree(snapshot_at) keeps only the latest known state per declaration_id; query with FINAL. indisppt has 0 published files as of 2026-09 — the country column is ready for when OMIE starts publishing it.