docs: handover post S0380.146..149

Captures the four slices that closed the oil-cohort Table 4f gap:
.146 primary loss for Table 4b regular boilers, .147 Eq D1 for
non-PCDB Table 4b, .148 liquid fuel boiler aux 100 kWh, .149
per-pump-age circulation + wet-boiler gate.

Documents the cohort-wide ~-£10/yr cost residual that S0380.149's
spec correctness exposed — the new next-slice front. Highlights the
user directive [[feedback-software-no-special-handling]] that
surfaced during S0380.147 and continued to apply through .149.

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

domain/sap10_calculator/docs/HANDOVER_POST_S0380_149.md

@@ -0,0 +1,280 @@
+# Handover — post Slices S0380.146..149
+
+Branch: `feature/per-cert-mapper-validation`. **HEAD `35ea664d`**.
+Predecessor: [`HANDOVER_POST_S0380_147.md`](HANDOVER_POST_S0380_147.md).
+
+## TL;DR
+
+Four slices landed on top of `1636cfbc` (the predecessor handover
+commit). The session closed the **oil cohort Table 4f auxiliary
+energy gap**: oil 1 SAP +2.66 → **+0.40**, oil pcdb 3 SAP +1.16 →
+**+0.39**, pcdb 1 +0.57 → +0.50, oil pcdb 1/2 +0.42 → +0.36. Cascade
+HW fuel cascade is now exact at the worksheet line ref for oil 1
+(3638.99 kWh/yr).
+
+The session also **applied spec-correct dispatch uniformly across the
+entire cohort** per the user's mid-session directive
+([[feedback-software-no-special-handling]]): "The software doesn't
+have special non-spec handling." This unmasked offsetting cascade gaps
+that the pre-fix `_DEFAULT_PUMPS_FANS_KWH_PER_YR = 130` and
+`_PUMPS_FANS_KWH_BY_MAIN_CATEGORY[2] = 160` hardcodes had been
+masking — solid fuel 2 regressed +2.64 → +3.15, electric storage
+cohort moved from ~zero to +0.45..+0.66 SAP, etc.
+
+| Slice | Commit | Scope |
+|---|---|---|
+| S0380.146 | `bd193e06` | SAP 10.2 Table 3 row 1 — primary loss for Table 4b non-PCDB regular boilers + cylinder. New `_TABLE_4B_COMBI_OR_CPSU_CODES` zero-loss exclusion set. |
+| S0380.147 | `7dceeff2` | SAP 10.2 Appendix D §D2.1 (2) Eq D1 — wire monthly winter/summer cascade for non-PCDB Table 4b boilers. New `tables/table_4b.py` carries 41-row (winter, summer) dict verbatim from spec p.168. `_apply_water_efficiency` refactored to `eq_d1_winter_summer_pct: Optional[tuple[float, float]]`. |
+| S0380.148 | `1b1f45b6` | SAP 10.2 Table 4f "Liquid fuel boiler – flue fan and fuel pump" 100 kWh/yr — added for Main 1 + Main 2 per Note c). New `is_liquid_fuel_code` in `tables/table_32.py`. |
+| **S0380.149** | **`35ea664d`** | **SAP 10.2 Table 4f circulation pump per pump age (41 / 165 / 115) + new `_is_wet_boiler_main` gate (Table 4a/4b code 101-141/151-161/191-196 + PCDB Table 322 + cat {1,2} fallback). Removes `_PUMPS_FANS_KWH_BY_MAIN_CATEGORY` + `_DEFAULT_PUMPS_FANS_KWH_PER_YR`. Mapper fix: "2012 or earlier" → int 1 (was silently 2).** |
+
+Extended handover suite at HEAD: **892 pass, 0 fail.** Pyright
+net-zero / net-improved.
+
+## Critical user directive (read first)
+
+**[[feedback-software-no-special-handling]]**: "The software doesn't
+have special non-spec handling." The BRE-approved Elmhurst lodging
+software follows spec exactly. When a spec-correct fix shifts a
+cohort cert pin, the pre-fix near-zero state was masking offsetting
+cascade gaps — NOT a deliberate non-spec rule. Apply spec uniformly +
+re-pin + document the unmasked gap as a follow-up.
+
+S0380.147 was initially scoped narrowly ("only fire Eq D1 when cylinder
+is present") to avoid shifting cert 0240/6035. The user pushed back;
+the cylinder gate was removed; cert 0240/6035 were re-pinned. Same
+discipline applies to S0380.149's broader cohort shift.
+
+## Current residual state at HEAD `35ea664d`
+
+### Cascade-OK tier (25 variants on pin grid) — sorted by |ΔSAP_c|
+
+| Variant | SAP code | ΔSAP_c | Δcost | ΔPE | Notes |
+|---|---:|---:|---:|---:|---|
+| ashp | 214 | +0.24 | -£5.57 | -12 | (closed) |
+| oil pcdb 1/2 | (PCDB) | +0.36 | -£8.32 | -67 | |
+| oil pcdb 3 | (PCDB) | +0.39 | -£8.91 | -67 | |
+| oil 1 | 127 | +0.40 | -£9.31 | -71 | |
+| solid fuel 4 | 633 | +0.45 | -£10.42 | -107 | room heater |
+| electric 1 | 191 | +0.45 | -£10.42 | -40 | electric boiler |
+| electric 8 | 409 | +0.49 | -£11.23 | -71 | |
+| solid fuel 11 | 634 | +0.48 | -£11.08 | -92 | room heater |
+| pcdb 1 | (PCDB) | +0.50 | -£11.10 | -93 | |
+| electric 7 | 408 | +0.54 | -£12.44 | -84 | |
+| solid fuel 6 | 160 | +0.54 | -£12.39 | -90 | |
+| solid fuel 9 | 636 | +0.55 | -£12.64 | -104 | room heater |
+| electric 6 | 404 | +0.57 | -£13.24 | -93 | |
+| solid fuel 10 | 634 | +0.58 | -£13.45 | -130 | room heater |
+| solid fuel 7 | 160 | +0.60 | -£14.07 | -118 | |
+| electric 9 | 421 | +0.63 | -£14.43 | -105 | |
+| electric 3 | 401 | +0.66 | -£15.13 | -115 | |
+| electric 5 | 402 | -0.68 | +£15.70 | +339 | regressed by .145 |
+| gshp | 211 | +1.15 | -£26.48 | -455 | open |
+| solid fuel 3 | 160 | +1.83 | -£42.19 | -1069 | PE outlier |
+| solid fuel 2 | 158 | +3.15 | -£72.53 | -1346 | PE outlier (regressed by .149) |
+| solid fuel 5 | 153 | +0.34 | -£7.93 | -42 | |
+| solid fuel 8 | 160 | +0.43 | -£9.89 | -89 | |
+| electric 2 | 524 | -0.18 | +£4.24 | +393 | warm-air ASHP |
+| solid fuel 4 | 633 | +0.45 | -£10.42 | -107 | room heater |
+
+Σ |ΔSAP_c| across 25 variants ≈ **15.4 SAP points** (was 10.7 pre-
+session — Note: appearance of "regression" is misleading because the
+pre-session pins on solid fuel + electric were masking offsetting
+bugs via the 130 kWh default. The new pins reflect the actual
+underlying cascade-vs-worksheet gap.)
+
+### Blocked tier (16 variants — `MissingMainFuelType`)
+
+Unchanged from previous handover. Categories: community heating × 5,
+electric storage 11-14, no system, oil 2-6, pcdb 3.
+
+## Pattern observed across the cohort
+
+After S0380.149's spec-correct dispatch, MANY variants share a
+**~-£10 to -£14 cost residual** (cascade UNDER worksheet by ~£10-14).
+This is a cohort-wide signal: there's a systematic gap somewhere
+producing ~£10/yr of cost the cascade is missing. Candidates:
+
+- **Space heating fuel kWh under-count**: cascade SH useful kWh tends
+  to be slightly above worksheet (e.g. oil 1 +87 kWh useful = +103
+  fuel = +£5.60 cost), but the cost residual is -£10 (cascade UNDER).
+  So SH fuel isn't the driver of the under-count.
+- **A possible (45) energy content or (62) HW demand under-count**.
+- **Standing charges** (Table 12 footnote) — cascade may not be
+  including off-peak / gas standing charges that the worksheet adds.
+- **Table 4f component I'm still missing** — keep-hot facility (600
+  kWh combi gas), warm-air heating fans (SFP × 0.4 × V), or solar HW
+  pump on certs with solar.
+
+This is the **next-slice front**: identify the cohort-wide cost
+deficit and close it.
+
+## Next-slice candidates ranked by leverage
+
+### 1. **Cohort-wide ~-£10/yr cost under-count** — highest leverage
+
+Affects ~15+ variants simultaneously. Probe a variant with high
+fidelity (oil 1, oil pcdb 1) line-by-line against the worksheet (240)
+SH cost / (247) HW cost / (249) pumps cost / (250) lighting cost /
+(251) standing charges → total (255). One of these line refs is
+under-counting.
+
+### 2. **solid fuel 2 +3.15 / 3 +1.83 PE outliers** — anthracite
+
+Both Table 4a codes 158/160. PE residuals -1346 / -1069 kWh/yr are
+huge. Likely Table 4b solid-fuel efficiency, Table 4f, or §9
+anthracite-specific secondary fraction.
+
+### 3. **electric 5 -0.68** — still open from S0380.145 regression
+
+Pre-S0380.145 was +0.07 (offsetting bugs). Post-slice with +0.4 K
+Table 4e adjustment applied: cascade now OVER worksheet SH by
+~248 kWh. Likely §9 MIT calc for fan-assisted storage heater R=0.40
+(code 402) OR Table 9b Tsc formula divergence.
+
+### 4. **gshp +1.15** — heat pump cascade
+
+PCDB Table 362 dispatch. Separate from the boiler cohort.
+
+### 5. **Community heating unblocking (5 variants)** — extractor work
+
+Extend extractor to capture §14.1 Community Heating block (heat-
+network codes 41-58).
+
+### 6. **Electric storage unblocking (variants 11-14)**
+
+Extend `_ELMHURST_MAIN_HEATING_EES_TO_FUEL_CODE` for EES codes WEA,
+REA, OEA.
+
+### 7. **Cert 0240 dual-main Q_space split**
+
+Cert 0240 has main_heating_fraction = 51%/49%. Spec Eq D1 says
+Q_space = (98c)m × (204) per Main 1's fraction. Cascade currently
+uses full (98c)m. Closing this might close the +£11 cost gap on cert
+0240 too.
+
+## Important diagnostic findings from this session
+
+1. **Cohort-wide spec correctness exposes the underlying cascade
+   gaps**. Pre-fix near-zero pins on solid fuel / electric were
+   coincidental — the broken 130 kWh default cancelled real cascade
+   gaps. Now that the pumps_fans dispatch is spec-correct, the
+   cascade-vs-worksheet diff is visible for the first time.
+
+2. **Pre-existing default fallbacks are landmines**. The 130 kWh and
+   160 kWh hardcodes silently mis-classified ~25 cohort variants —
+   each shift looked like a regression but was actually the truth
+   becoming visible.
+
+3. **PCDB-listed certs need a separate wet-boiler discriminator**.
+   `sap_main_heating_code` is None on PCDB-listed mains; the
+   `_is_wet_boiler_main` helper had to add a Table 322 lookup to
+   correctly identify them as wet.
+
+4. **The "next oil property" pattern**: focus on closing one variant
+   at a time, but the spec fix typically applies cohort-wide. Two
+   slices (one spec rule each) closed five oil variants together.
+
+## Standard slice workflow
+
+1. Read spec page + identify rule
+2. Probe one cluster variant; verify diagnosis via monkey-patch
+3. Write failing AAA test (literal `# Arrange / # Act / # Assert`)
+4. Implement helper / dispatch entry / mapper extension
+5. Re-pin affected variants (DO NOT widen tolerance)
+6. Run extended handover suite (command below)
+7. Pyright net-zero check (`git stash` → pyright → `git stash pop` →
+   pyright; or stripping line numbers from diff to find genuinely
+   new errors after a refactor)
+8. Commit with spec citation +
+   `Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>`
+9. Update `project-heating-systems-corpus` + `MEMORY.md` index
+
+## Test baseline at HEAD `35ea664d`
+
+```bash
+PYTHONPATH=/workspaces/model python -m pytest \
+    backend/documents_parser/tests/test_summary_pdf_mapper_chain.py \
+    backend/documents_parser/tests/test_heating_systems_corpus.py \
+    backend/documents_parser/tests/test_elmhurst_extractor.py \
+    backend/documents_parser/tests/test_elmhurst_end_to_end.py \
+    domain/sap10_calculator/worksheet/tests/test_e2e_elmhurst_sap_score.py \
+    domain/sap10_calculator/worksheet/tests/test_heat_transmission.py \
+    domain/sap10_calculator/worksheet/tests/test_internal_gains.py \
+    domain/sap10_calculator/worksheet/tests/test_solar_gains.py \
+    domain/sap10_calculator/worksheet/tests/test_dimensions.py \
+    domain/sap10_calculator/worksheet/tests/test_rating.py \
+    domain/sap10_calculator/worksheet/tests/test_ventilation.py \
+    domain/sap10_calculator/worksheet/tests/test_appendix_h_solar.py \
+    domain/sap10_calculator/worksheet/tests/test_mev.py \
+    domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py \
+    domain/sap10_calculator/rdsap/tests/test_golden_fixtures.py \
+    domain/sap10_calculator/tests/test_pcdb_table_322_lookup.py \
+    domain/sap10_calculator/tests/test_pcdb_table_329_lookup.py \
+    domain/sap10_calculator/tests/test_table_12a.py \
+    --no-cov -q
+```
+
+Expected: **892 pass, 0 fail**.
+
+## Memories to load (in order)
+
+```
+project-heating-systems-corpus            # HEAD 35ea664d
+feedback-sap-10-2-only-never-10-3         # CRITICAL — never reference SAP 10.3
+feedback-software-no-special-handling     # CRITICAL — apply spec uniformly, no empirical gates
+feedback-worksheet-not-api-reference
+feedback-spec-citation-in-commits
+feedback-verify-handover-claims
+feedback-zero-error-strict                # TARGET: ΔSAP_c < 1e-4 vs worksheet
+feedback-commit-per-slice
+feedback-aaa-test-convention
+feedback-e2e-validation-philosophy
+feedback-abs-diff-over-pytest-approx
+feedback-spec-floor-skepticism
+feedback-golden-residuals-near-zero
+feedback-one-e-minus-4-across-the-board
+reference-unmapped-sap-code
+reference-unmapped-api-code
+project-oil-price-spec-divergence
+```
+
+## What NOT to do
+
+- **Don't reference SAP 10.3** — track 10.2 deliberately
+- **Don't widen pin tolerances** — re-pin smaller or find the spec gap
+- **Don't add empirical gates** to keep cohort pins stable when a
+  spec rule clearly applies. The cohort-wide ~-£10 cost shift after
+  S0380.149 is NOT a regression — it's spec correctness unmasking
+  offsetting bugs. Don't reintroduce the 130 default to "fix" it.
+- **Don't re-investigate Slices .91..149** — all settled
+- **Don't add new helpers to `domain/sap10_ml/`** — on deprecation
+  path; `domain/sap10_calculator/tables/` is the canonical home
+- **Don't treat ΔSAP=0.07 as "closed"** — target is <1e-4 vs worksheet
+
+## Spec source quick-reference
+
+All under `domain/sap10_calculator/docs/specs/`:
+
+- **SAP 10.2 full spec**: `sap-10-2-full-specification-2025-03-14.pdf`
+  - **§4** (p.135-137) — water heating worksheet (45..65)
+  - **§9** (p.155+) — MIT calc, Tables 9/9a/9b/9c
+  - **§9.4.11** (p.30) — Boiler interlock: -5pp to BOTH SH and DHW
+  - **§A.2.2** (~p.189) — Forced-secondary set
+  - **Table 3** (p.160) — Primary circuit loss; zero-loss list
+  - **Table 4a** (p.163-170) — heating systems incl. R column
+  - **Table 4b** (p.168) — gas/liquid boilers seasonal efficiency
+  - **Table 4c** (p.169-170) — Efficiency adjustments
+  - **Table 4d** (p.170) — heat-emitter R
+  - **Table 4e** (p.170-173) — heating system controls + temp adjustment
+  - **Table 4f** (p.174) — pumps + fans (S0380.148..149 territory)
+  - **Table 9c** (p.184) — heating requirement (step 8 Table 4e adj)
+  - **Table 11** (p.188) — secondary heating fraction
+  - **Table 12** (p.191) — SAP rating fuel prices + standing charges
+  - **Table 12a** (p.191) — high/low-rate fraction by system × tariff
+  - **Appendix D §D2.1 (2)** (p.57) — Eq D1 monthly water eff cascade
+- **RdSAP 10 spec**: `RdSAP 10 Specification 10-06-2025.pdf`
+  - **§10.11 Table 29** (p.56) — Heating/HW parameters; inaccessible cylinder
+  - **§19 Table 32** (p.95) — RdSAP10 fuel prices / CO2 / PE
+
+## Good luck.