id: CORE-001D
title: External Boundary and Persistence Cleanup for Decimal Unit Types
status: backlog
priority: P2
effort: M
depends_on:
  - CORE-001B
  - CORE-001C
tags: [core, decimal, persistence]
summary: Make Decimal/unit-safe values reliable across persistence, APIs, and provider boundaries.
acceptance_criteria:
  - Persistence format for unit-safe values is explicit and stable.
  - Decimal-bearing JSON/API serialization is documented and tested.
  - Float-heavy integrations have named conversion boundaries.
  - Remaining raw-float domain hotspots are identified or removed.