P2.2: migrate golden fixtures to SAP 10.2 spec prices; loose smoke test

ADR-0010 §10: the cert-based fixtures contained compensating errors
under cert-cal prices and are scheduled for replacement by BRE
worked-example fixtures (P5). Until P5 lands they stay as a loose
smoke test catching catastrophic regressions only.

Changes:
  - Swap prices=cert_calibration_prices() → prices=SAP_10_2_SPEC_PRICES.
    Last external consumer of cert_calibration_prices — P2.3 can now
    delete table_12_cert_calibration.py cleanly.
  - Loosen tolerance: SAP ±1 → ±5, PE ±10 → ±25. The cert-cal prices
    had been numerically tuned around these specific certs, so spec
    prices alone produce a -3 to +3 SAP drift across the set.
  - Retire 9390-2722-3520-2105-8715 early (heat-network mid-floor
    flat). It drifted to SAP residual -7 because cert-cal had absorbed
    heat-network DLF + Table 12c interactions. Cert JSON remains in
    fixtures/golden/ per ADR-0010 §10; a BRE worked-example covering
    the heat-network path will subsume it during P5.

Remaining 6 fixtures pass at ±5 SAP under spec prices. The whole
suite retires when P5 lands.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

packages/domain/src/domain/sap/rdsap/tests/test_golden_fixtures.py

@@ -1,23 +1,31 @@
-"""Regression-anchor tests for a small set of corpus certs whose
-SAP rating and primary-energy values our calculator currently produces
-within tolerance of what Elmhurst lodged.
+"""Loose smoke-test regression anchors for a small set of corpus certs.
 
-Purpose: catch regressions silently introduced by future slices. If a
-slice that's meant to improve aggregate MAE accidentally pushes a
-previously-correct cert outside the tolerance, this suite fails and we
-can decide consciously whether the trade-off is worth it.
+**Retiring**: per ADR-0010 §10 these cert-based fixtures contained
+compensating errors against the cert-cal-prices state of the calculator
+and are scheduled for replacement by BRE worked-example fixtures (P5).
+Until P5 lands, the fixtures stay in place as a *loose* smoke test —
+catching only catastrophic regressions, not per-line spec-correctness
+breaks.
 
-Tolerance rationale:
-- SAP rounded-integer residual ≤ 1 — the score the cert lodges; integer
-  rounding means an exact "0" check would over-fit to integer flips.
-- PE residual ≤ 10 kWh/m² — looser than ideal but reflects current
-  calculator capability; tightens as we close the PE bias.
+Purpose: catch wholesale-broken slices (e.g. a refactor that drops a
+worksheet stage entirely) between now and P5. Per-section verification
+during the spec sweep should lean on BRE worked-example unit tests, not
+on these fixtures.
+
+Tolerance rationale (per ADR-0010 §10):
+- SAP rounded-integer residual ≤ 5 — was ±1 under cert-cal prices.
+  Loosened because spec prices produce ±2-3 SAP drift on these certs
+  (the cert-cal prices had been numerically tuned around the same
+  certs).
+- PE residual ≤ 25 kWh/m² — was ±10. Loosened on the same logic.
 
 Selection criteria (see docs/sap-spec/PARITY_FINDINGS.md): from a
 1000-cert random sample these 7 certs satisfied
   |continuous SAP residual| ≤ 1.0 AND |PE residual| ≤ 10
   AND (main_heating_category != 4 OR main_heating_data_source != 1)
-i.e. non-PCDB-heat-pump, lowest combined-residual quartile of the sample.
+under the **cert-cal prices** that have since been deleted. They are
+no longer a "lowest-residual" set under spec prices, but stable enough
+to catch obvious regressions.
 
 Each cert is a stored JSON document under
 `fixtures/golden/<certificate_number>.json` — frozen at extraction time
@@ -35,12 +43,15 @@ import pytest
 
 from datatypes.epc.domain.mapper import EpcPropertyDataMapper
 from domain.sap.calculator import calculate_sap_from_inputs
-from domain.sap.rdsap.cert_to_inputs import cert_to_inputs
-from domain.sap.tables.table_12_cert_calibration import cert_calibration_prices
+from domain.sap.rdsap.cert_to_inputs import SAP_10_2_SPEC_PRICES, cert_to_inputs
 
 _FIXTURES_DIR = Path(__file__).parent / "fixtures" / "golden"
-_SAP_TOLERANCE = 1
-_PE_TOLERANCE_KWH_PER_M2 = 10.0
+# Loose smoke-test tolerances per ADR-0010 §10; was ±1 / ±10 under
+# cert-cal prices, which had been numerically tuned around these
+# specific certs. Tightens when BRE worked-example fixtures (P5)
+# replace this suite.
+_SAP_TOLERANCE = 5
+_PE_TOLERANCE_KWH_PER_M2 = 25.0
 
 
 @dataclass(frozen=True)
@@ -99,13 +110,13 @@ _EXPECTATIONS: tuple[_GoldenExpectation, ...] = (
         expected_pe_resid_kwh_per_m2=+8.18,
         notes="Semi-detached, TFA 102, age C, gas PCDB-listed.",
     ),
-    _GoldenExpectation(
-        cert_number="9390-2722-3520-2105-8715",
-        actual_sap=67,
-        expected_sap_resid=0,
-        expected_pe_resid_kwh_per_m2=+7.90,
-        notes="Mid-floor flat, TFA 75, age D, heat network (cat 6, sap_code 301).",
-    ),
+    # Retired early at P2.2: 9390-2722-3520-2105-8715 (mid-floor flat,
+    # heat network cat 6 sap_code 301). Drifted to SAP residual -7
+    # under SAP 10.2 spec prices because cert-cal had absorbed
+    # heat-network DLF + Table 12c interactions on this cert. Cert JSON
+    # remains in fixtures/golden/ as reference data per ADR-0010 §10;
+    # will be subsumed by a BRE worked-example fixture covering the
+    # heat-network path during P5.
 )
 
 
@@ -122,12 +133,13 @@ def _load_cert(cert_number: str) -> dict[str, Any]:
     ids=lambda e: e.cert_number,
 )
 def test_golden_cert_stays_within_tolerance(expectation: _GoldenExpectation) -> None:
-    # Arrange — load the frozen cert JSON, map to EpcPropertyData, run the
-    # calculator end-to-end with cert-calibration prices (the parity-
-    # validation mode the existing probe uses).
+    # Arrange — load the frozen cert JSON, map to EpcPropertyData, run
+    # the calculator end-to-end with SAP 10.2 (14-03-2025) spec prices
+    # per ADR-0010. Recorded residuals on _GoldenExpectation predate the
+    # cert-cal deletion and are informational only.
     doc = _load_cert(expectation.cert_number)
     epc = EpcPropertyDataMapper.from_api_response(doc)
-    inputs = cert_to_inputs(epc, prices=cert_calibration_prices())
+    inputs = cert_to_inputs(epc, prices=SAP_10_2_SPEC_PRICES)
 
     # Act
     result = calculate_sap_from_inputs(inputs)