docs: record CORE-002B completion

docs/roadmap/backlog/CORE-002C-historical-workspace-share-conversion.yaml

@@ -0,0 +1,22 @@
+id: CORE-002C
+title: Historical Workspace Collateral to GLD Share Conversion Alignment
+status: backlog
+priority: P1
+effort: M
+depends_on:
+  - CORE-002A
+  - CORE-001C
+tags:
+  - core
+  - units
+  - backtesting
+  - event-comparison
+summary: Align workspace-derived collateral defaults with explicit GLD share semantics in historical/backtest-style paths so workspace collateral is converted through named metadata rather than ad hoc share assumptions.
+acceptance_criteria:
+  - Backtest/event-style workspace seeding uses explicit metadata-backed collateral/share conversion rules.
+  - Historical/unit materialization remains compatible while avoiding ambiguous share-vs-ounce assumptions.
+  - Unsupported or missing conversion metadata fails closed.
+  - Tests cover workspace-derived default seeding and changed browser-visible read paths where relevant.
+technical_notes:
+  - Likely file targets include `app/domain/backtesting_math.py`, `app/services/backtesting/ui_service.py`, `app/services/backtesting/comparison.py`, and `app/services/event_comparison_ui.py`.
+  - Reuse the instrument metadata seam introduced in `CORE-002A`/`CORE-002B`.