v1.0.0 — FixedDecimal money type (lara100 v2) — AID-237 BREAKING: monetary model attributes now expose FixedDecimal instead of int. DB storage unchanged (integer base-100 cents). Per-line taxable amount rounds HalfUp (EU/Spain) instead of truncating. See docs/ADR-009 + docs/upgrade-1.0-fixeddecimal.md.