feat(PORT-004C): seed workspace routes from portfolio settings

tests/test_backtest_ui.py

@@ -54,6 +54,32 @@ def test_backtest_non_default_template_slug_runs_successfully() -> None:
     assert result.run_result.template_results[0].template_slug == non_default_slug
 
 
+def test_backtest_page_service_keeps_fixture_history_while_using_caller_portfolio_inputs() -> None:
+    service = BacktestPageService()
+
+    result = service.run_read_only_scenario(
+        symbol="GLD",
+        start_date=date(2024, 1, 2),
+        end_date=date(2024, 1, 8),
+        template_slug="protective-put-atm-12m",
+        underlying_units=9680.0,
+        loan_amount=222000.0,
+        margin_call_ltv=0.80,
+    )
+
+    assert result.entry_spot == 100.0
+    assert result.scenario.initial_portfolio.underlying_units == 9680.0
+    assert result.scenario.initial_portfolio.loan_amount == 222000.0
+    assert result.scenario.initial_portfolio.margin_call_ltv == 0.80
+    assert [point.date.isoformat() for point in result.run_result.template_results[0].daily_path] == [
+        "2024-01-02",
+        "2024-01-03",
+        "2024-01-04",
+        "2024-01-05",
+        "2024-01-08",
+    ]
+
+
 @pytest.mark.parametrize(
     ("kwargs", "message"),
     [