Slice 20: lodge per-window u_value on mixed-glazing fixtures

The 000474 / 000477 / 000487 fixtures lodged sap_windows without an
explicit u_value, relying on make_window's default u_value=2.8 (raw,
pre-curtain-resistance). PDF lodges TWO window types per fixture:
- Windows 1 (g_⊥=0.72): post-2002 double, raw U=2.0 → U_eff=1.8519
- Windows 2 (g_⊥=0.76): pre-2002 double, raw U=2.8 → U_eff=2.5180
- (000487 Windows 2 special: post-2022, raw U=1.4 → U_eff=1.3258)

Lodging all windows at u_value=2.8 over-counted window heat loss
(LINE_27/LINE_33) by 1.5-3% on mixed-glazing fixtures. The previous
test_section_3 LINE_33 pin passed because it used a pre-computed
WINDOW_AVG_RAW_U_VALUE constant rather than cert-derived sap_windows.

Impact on `sap.space_heating_kwh_per_yr` vs PDF:

  fixture | before     | after      | gap before | gap after
  --------|------------|------------|------------|----------
  000474  | 10765.85   | 10615.86   |  +152.99   | +3.00  (-98%)
  000477  | 10318.34   | 10106.89   |  +207.14   | -4.31  (-98%)
  000480  | 12397.99   | 12397.99   |    -0.58   | -0.58  (unchanged; all windows raw 2.8)
  000487  | 12606.95   | 12303.35   | +1772.17   | +1468.57 (RR defect remains)
  000490  | 11184.06   | 11184.06   |    +0.78   | +0.78  (unchanged)
  000516  | 12372.62   | 12372.62   |   -37.70   | -37.70 (unchanged)

The 000474 / 000477 cascade biases collapse by 98% — remaining 3-4 kWh
residuals are precision-level and likely propagate from §4 HW or §7
T_i drift (sub-0.1°C). 000487 still 13.6% over because the RR
lodgement defect (no detailed_surfaces, missing exposed_floor on
Ext1, missing roof_insulation, U=0.86 second gable variant) is a
separate slice.

Cascade pin count stays at 48 fail / 18 pass because abs=1e-4 is
tight — 3 kWh > 1e-4. But the underlying numeric residual dropped
50×. Subsequent pins (main_fuel, ecf, cost, sap_continuous) will
also tighten as this cascade flows downstream.

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

packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000474.py

@@ -323,9 +323,13 @@ LINE_73_M_TOTAL_INTERNAL_GAINS_W: tuple[float, ...] = (
 #   "Double with unknown" g=0.76: E 3.74, NW 1.76
 # All PVC frame. No roof windows, no rooflights.
 SECTION_6_VERTICAL_WINDOWS: tuple[SapWindow, ...] = (
-    make_window(orientation=3, width=3.74, height=1.0, solar_transmittance=0.72),
-    make_window(orientation=4, width=0.50, height=1.0, solar_transmittance=0.72),
-    make_window(orientation=8, width=1.98, height=1.0, solar_transmittance=0.72),
+    # Windows 1 (PDF (27) U_eff=1.8519, raw U=2.0 post-2002 default; g_⊥=0.72):
+    # 3 entries, total area 6.22 m².
+    make_window(orientation=3, width=3.74, height=1.0, solar_transmittance=0.72, u_value=2.0),
+    make_window(orientation=4, width=0.50, height=1.0, solar_transmittance=0.72, u_value=2.0),
+    make_window(orientation=8, width=1.98, height=1.0, solar_transmittance=0.72, u_value=2.0),
+    # Windows 2 (PDF (27) U_eff=2.5180, raw U=2.8 pre-2002 default; g_⊥=0.76):
+    # 2 entries, total area 5.50 m². make_window default u_value=2.8 matches.
     make_window(orientation=3, width=3.74, height=1.0, solar_transmittance=0.76),
     make_window(orientation=8, width=1.76, height=1.0, solar_transmittance=0.76),
 )

packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000477.py

@@ -291,8 +291,12 @@ LINE_73_M_TOTAL_INTERNAL_GAINS_W: tuple[float, ...] = (
 #   "Double with unknown" g=0.76: W 1.17
 # All PVC frame. No roof windows, no rooflights.
 SECTION_6_VERTICAL_WINDOWS: tuple[SapWindow, ...] = (
-    make_window(orientation=3, width=1.28, height=1.0, solar_transmittance=0.72),
-    make_window(orientation=7, width=6.76, height=1.0, solar_transmittance=0.72),
+    # Windows 1 (PDF (27) U_eff=1.8519, raw U=2.0 post-2002; g_⊥=0.72):
+    # area 1.28 + 6.76 = 8.04 m².
+    make_window(orientation=3, width=1.28, height=1.0, solar_transmittance=0.72, u_value=2.0),
+    make_window(orientation=7, width=6.76, height=1.0, solar_transmittance=0.72, u_value=2.0),
+    # Windows 2 (PDF (27) U_eff=2.5180, raw U=2.8 pre-2002; g_⊥=0.76):
+    # area 1.17 m². make_window default u_value=2.8 matches.
     make_window(orientation=7, width=1.17, height=1.0, solar_transmittance=0.76),
 )
 SECTION_6_ROOF_WINDOWS: tuple[RoofWindowInput, ...] = ()

packages/domain/src/domain/sap/worksheet/tests/_elmhurst_worksheet_000487.py

@@ -310,8 +310,12 @@ LINE_73_M_TOTAL_INTERNAL_GAINS_W: tuple[float, ...] = (
 #   "Double between 2002" g=0.72: S 6.69
 # All PVC frame. No roof windows, no rooflights.
 SECTION_6_VERTICAL_WINDOWS: tuple[SapWindow, ...] = (
+    # Windows 1 (PDF (27) U_eff=2.5180, raw U=2.8 pre-2002; g_⊥=0.76):
+    # area 0.77 m². make_window default u_value=2.8 matches.
     make_window(orientation=5, width=0.77, height=1.0, solar_transmittance=0.76),
-    make_window(orientation=5, width=6.69, height=1.0, solar_transmittance=0.72),
+    # Windows 2 (PDF (27) U_eff=1.3258, raw U=1.4 post-2022; g_⊥=0.72):
+    # area 6.69 m² (1.65 + 5.04). Replaced post-2022 → tighter U.
+    make_window(orientation=5, width=6.69, height=1.0, solar_transmittance=0.72, u_value=1.4),
 )
 SECTION_6_ROOF_WINDOWS: tuple[RoofWindowInput, ...] = ()
 SECTION_6_ROOFLIGHTS: tuple[RooflightInput, ...] = ()