WS-C deferred adjudications and the reconciliation layer

[juaristi22]

Central registry of the adjudications deferred during the #622 build-out (PR #735), to be reviewed after the spine (#145/WS-E) and calibration workstreams complete. Each item links its signed rationale in the committed resources (uk/target_reference_membership.json, uk/ledger_compile_parity_*_signed_differences.json). Items graduate to their own issues when they become actionable.

1. Property-income ×1.9 undercount → reconciliation home. The incumbent scales SPI Table 3.7 amounts ×1.9 (trace: policyengine-uk-data#311 / policyengine-uk-data#230 — SPI covers only taxpayers with liability; HMRC Property Rental Income Statistics show £46.68bn vs SPI ~£24.5bn for 2020-21). The family is signed-excluded from activation. Doctrine-clean paths: a chronicle package for the rental statistics + a declared reconciliation, or a declared value-scaling operation citing Add coverage-universe targets for uninsured and private coverage #230. This is the anchor case for the reconciliation layer.
2. Region-grain activation for the 18 two-level contract targets — Fixture A's 131 region×age production rows are structurally unmatched while activation pins country grain.
3. ons.population.scotland_households_3plus_children — the contract wants a household-composition fact that does not exist at ≤2025; needs a chronicle-side fact or an adjudicated alternative source.
4. TCL year surface — the incumbent pins the April-2025 publication values at {2026}; the Ledger side activates at 2025. Revisit when a 2026-vintage publication exists.
5. CGT 2025 level — identity hold (£65.937bn, the 2023-24 outturn) vs the incumbent's uprated £67.73bn. Resolves with the uprating/aging-index layer decision.
6. The 347 uprating holds — currently explicit identity holds; per-family index declarations belong to the materialization layer.
7. Salary-sacrifice canonical source — HMRC-table facts vs the incumbent's OBR-forecast rows (value ratios 0.81–1.14); pick per target when calibration binds them.
8. UC payment-band source-only rows — 12 'No payment' / 'or over' facts skipped in fan-out (no safe incumbent inverse).
9. UC family-split month choice — +2.6–15% drift from latest-month resolution vs the incumbent's pinned publication month; candidate for calendar-average treatment as fact history grows.
10. Calibrate the UK national build from Ledger-backed targets #623 disposition — the calibration seam landed via Add the UK national calibration step over ledger-backed target references #729; close or narrow Calibrate the UK national build from Ledger-backed targets #623 accordingly.

Refs: #622, #735, #665, #731.
11. TCL retirement at the year move — the limit is abolished from 2026-04-06 (Budget 2025; policyengine-uk-data#465), so at period 2026 the 15 TCL targets are structurally zero: the references must retire or re-vintage with the calibration-year move (WS-F/#723). Add the contract-side guard from uk-data#465's step 2: a test refusing a reference whose binding variable is structurally zero at the reference period. (Our 2025 activation is unaffected — the limit is in force in FY 2025-26; when uk-data#465 moves the incumbent's values to 2025, Fixture B's 15 TCL ledger-only additions become matched rows at the next pin refresh.)
12. UC element-count targets (housing, LCWRA, carer, childcare — policyengine-uk-data#466, microcosm#738 step 3): no contract declarations exist; pipeline is chronicle facts first (childcare's published 160k series needs no API key — easiest first package; the rest need Stat-Xplore UC_Households exports), then a contract amendment per the #727 precedent, then references auto-activate on regeneration. Facts requested: PolicyEngine/chronicle#187. Also fold uk-data#466's family-type/caseload sum-consistency into item 9's calendar-average treatment.

13. water_and_sewerage_charges raw-mapping divergence (WS-E, surfaced by Retarget the UK build to FRS 2024-25: re-pin raw vintages, regenerate parity instruments, re-measure gate baselines #723). The microcosm spine's unweighted nonzero share is 0.8779 vs the incumbent eFRS 2024-25 reference's 0.7769 (+0.1009). Of the 27 columns beyond ±0.02 in the Retarget the UK build to FRS 2024-25: re-pin raw vintages, regenerate parity instruments, re-measure gate baselines #723 parity screen this is the only one produced by frs_spine — a direct raw FRS mapping, not an imputation — so it falls outside every signed method class (E5 wealth, E6 consumption, E7 SPI-channel QRF). It is not a composition or channel artifact: the share is uniform across our two channels (survey 0.8784, SPI-synthetic 0.8770) and the synthetic mix matches the reference almost exactly (0.3804 vs 0.3801), so channel-mix dilution is excluded. Candidate mechanism, unverified: the incumbent zeroing water charges where they are bundled — Scotland/NI, or by tenure — against our unconditional watsewrt/cwatamtd/csewamt mapping. Doctrine applies: verify against the FRS 2024-25 dictionary and raw aggregates, then either fix-and-sign or register a signed difference — never replicate silently, never silently correct. Evidence: microcosm#733 (comment 5379276066), data/ukds/acceptance/723-frs-2024-25/shares-a.json. Blocks nothing today; must resolve before Assemble the microcosm-built UK spine: whole-spine parity and swap acceptance #686 signs whole-spine parity.

[juaristi22]

Item 10 resolved: #623 narrowed to run-readiness (not closed) — the tooling is delivered by draft PR #743 (doctrine, live parity trio, US-format diagnostics with the chronicle pin, #578 rule-1 scorer, staging-candidate posture, runbook); the licensed armed run is held until WS-E E8 (#684) + E10 (#686) complete or María names a different base. #623 stays open for the run + acceptance evidence; the aggregate-scaler ruling (item context) remains open on #623 itself.