Isolate residual S/R target selection

tests/unit/test_backtest_service.py

@@ -765,6 +765,8 @@ def test_sr_research_variant_is_explicit_and_validated(monkeypatch):
         "legacy_range_grid_neutral",
         "production_range504",
         "rewrite_range504_legacy_primary",
+        "rewrite_range504_structural_legacy_primary",
+        "rewrite_range504_structural_primary2",
     ):
         monkeypatch.setenv("BACKTEST_SR_VARIANT", variant)
         assert bt._sr_research_variant() == variant
@@ -776,6 +778,10 @@ def test_sr_research_variant_is_explicit_and_validated(monkeypatch):
 def test_range_factor_detector_mapping_is_explicit():
     assert bt._sr_detector_variant("production_range504") == "production_control"
     assert bt._sr_detector_variant("rewrite_range504_legacy_primary") == "rewrite"
+    assert bt._sr_detector_variant(
+        "rewrite_range504_structural_legacy_primary"
+    ) == "rewrite"
+    assert bt._sr_detector_variant("rewrite_range504_structural_primary2") == "rewrite"
     assert bt._sr_detector_variant("soft_zones_legacy_primary") == "soft_zones"
 
 
@@ -789,6 +795,10 @@ def test_range_factor_gate_is_research_arm_only():
     below = bt.RANGE_FACTOR_MIN_LOG - 0.01
     assert not bt._range_factor_allows("production_range504", below)
     assert not bt._range_factor_allows("rewrite_range504_legacy_primary", below)
+    assert not bt._range_factor_allows(
+        "rewrite_range504_structural_primary2",
+        below,
+    )
     assert bt._range_factor_allows(
         "production_range504",
         bt.RANGE_FACTOR_MIN_LOG,
@@ -796,6 +806,18 @@ def test_range_factor_gate_is_research_arm_only():
     assert bt._range_factor_allows("production_control", below)
 
 
+def test_residual_arms_change_only_the_primary_rr_floor():
+    activation = {"min_rr": 2.0}
+    assert bt._primary_min_rr_for_variant(
+        "rewrite_range504_structural_legacy_primary",
+        activation,
+    ) == 1.5
+    assert bt._primary_min_rr_for_variant(
+        "rewrite_range504_structural_primary2",
+        activation,
+    ) == 2.0
+
+
 @pytest.mark.parametrize(
     ("variant", "neutral_strength"),
     [