fix: restore workspace nav and correct overview spot fallback

tests/test_overview_workspace.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from app.models.portfolio import PortfolioConfig
+from app.pages.overview import _resolve_overview_spot
+from app.services.alerts import build_portfolio_alert_context
+
+
+def test_overview_falls_back_to_configured_entry_price_when_live_quote_units_do_not_match() -> None:
+    config = PortfolioConfig(entry_price=4400.0, gold_ounces=220.0, entry_basis_mode="weight", loan_amount=145000.0)
+
+    spot_price, source, updated_at = _resolve_overview_spot(
+        config,
+        {"price": 404.19, "source": "yfinance", "updated_at": "2026-03-24T00:00:00+00:00"},
+    )
+    portfolio = build_portfolio_alert_context(
+        config,
+        spot_price=spot_price,
+        source=source,
+        updated_at=updated_at,
+    )
+
+    assert spot_price == 4400.0
+    assert source == "configured_entry_price"
+    assert portfolio["gold_value"] == 968000.0
+    assert portfolio["net_equity"] == 823000.0
+    assert round(float(portfolio["margin_call_price"]), 2) == 878.79