id: CORE-002A
title: Overview GLD Share Quote Conversion Seam
status: done
priority: P0
effort: S
depends_on:
  - CORE-001A
  - CORE-001B
  - CORE-001C
tags:
  - core
  - units
  - pricing
  - overview
summary: Overview now treats GLD quotes explicitly as USD/share and converts them to USD/ozt through instrument metadata.
completed_notes:
  - Added `app/domain/instruments.py` with explicit instrument metadata for GLD.
  - Encoded `1 GLD share = 0.1 ozt` and fail-closed conversions between share quantities, share prices, and troy-ounce values.
  - Updated overview quote resolution to require explicit `quote_unit` metadata before converting share quotes to collateral spot values.
  - Added quote payload normalization in `DataService` so cached legacy GLD quotes are upgraded safely with `quote_unit: share`.
  - Replaced the previous ratio-based overview fallback heuristic with an explicit metadata-backed conversion seam.
  - Added focused unit tests plus live Playwright coverage on `main`.