feat(CORE-002): add GLD share quote conversion seam

tests/test_portfolio_math.py

@@ -1,12 +1,16 @@
 from __future__ import annotations
 
+from decimal import Decimal
+
+from app.domain.backtesting_math import PricePerAsset
+from app.domain.instruments import price_per_weight_from_asset_price
 from app.domain.portfolio_math import (
     build_alert_context,
     portfolio_snapshot_from_config,
     strategy_metrics_from_snapshot,
 )
+from app.domain.units import BaseCurrency, WeightUnit
 from app.models.portfolio import PortfolioConfig
-from app.pages.common import strategy_catalog
 
 
 def test_portfolio_snapshot_from_config_preserves_weight_price_and_margin_values() -> None:
@@ -37,7 +41,27 @@ def test_build_alert_context_uses_unit_safe_gold_value_calculation() -> None:
     assert round(float(context["margin_call_price"]), 2) == 878.79
 
 
+def test_build_alert_context_accepts_explicit_gld_share_quote_conversion() -> None:
+    config = PortfolioConfig(entry_price=4400.0, gold_ounces=220.0, entry_basis_mode="weight", loan_amount=145000.0)
+    share_quote = PricePerAsset(amount=Decimal("404.19"), currency=BaseCurrency.USD, symbol="GLD")
+    ounce_spot = price_per_weight_from_asset_price(share_quote, per_unit=WeightUnit.OUNCE_TROY)
+
+    context = build_alert_context(
+        config,
+        spot_price=float(ounce_spot.amount),
+        source="yfinance",
+        updated_at="2026-03-24T00:00:00+00:00",
+    )
+
+    assert context["spot_price"] == 4041.9
+    assert context["gold_value"] == 889218.0
+    assert context["net_equity"] == 744218.0
+    assert context["quote_source"] == "yfinance"
+
+
 def test_strategy_metrics_from_snapshot_preserves_minus_20pct_protective_put_example() -> None:
+    from app.pages.common import strategy_catalog
+
     strategy = next(item for item in strategy_catalog() if item["name"] == "protective_put_atm")
     snapshot = {
         "gold_value": 215000.0,