docs: split CORE-002 into rollout slices

docs/roadmap/done/CORE-002A-overview-quote-conversion.yaml

@@ -0,0 +1,22 @@
+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`.