Add S/R v2 research and validation harness

tests/unit/test_backtest_service.py

@@ -730,6 +730,23 @@ def test_window_setups_too_short_returns_empty():
     assert bt._window_setups([], {}, {}) == []
 
 
+def test_sr_research_variant_is_explicit_and_validated(monkeypatch):
+    monkeypatch.setenv("BACKTEST_SR_VARIANT", "production_control")
+    assert bt._sr_research_variant() == "production_control"
+    monkeypatch.setenv("BACKTEST_SR_VARIANT", "not-a-variant")
+    with pytest.raises(ValueError, match="Unknown BACKTEST_SR_VARIANT"):
+        bt._sr_research_variant()
+
+
+def test_backtest_entry_bounds_validate_dates(monkeypatch):
+    monkeypatch.setenv("BACKTEST_ENTRY_START", "2024-07-01")
+    monkeypatch.setenv("BACKTEST_ENTRY_END", "2024-12-31")
+    assert bt._backtest_entry_bounds() == (date(2024, 7, 1), date(2024, 12, 31))
+    monkeypatch.setenv("BACKTEST_ENTRY_START", "2025-01-01")
+    with pytest.raises(ValueError, match="on or before"):
+        bt._backtest_entry_bounds()
+
+
 def test_replay_ticker_candidates_carry_gate_fields():
     """The ablation recomputes floors from candidate fields — a candidate missing
     action/risk_level silently zeroes the ablation rows (July 2026 regression)."""