Add Belgium pension, GRAPA, and source handoffs

[MaxGhenis]

Summary

• replace the intermediary SFPD pension CSV with the official February 2025 monthly-statistics PDF and direct source-cell selectors;
• add four exact February 2025 facts: employee/self-employed pension beneficiaries and monthly expenditure, plus GRAPA beneficiaries and monthly expenditure;
• add a source-scoped European document-number format for SFPD while preserving the original default grammar and existing single-dot behavior;
• audit the six original Belgium selectors from Author ledger-be source packages for open Belgian aggregates with geography vintages #69: all remain registered, unique, valid, and resolve 587 facts on current main;
• add a validated six-artifact offline-fetch handoff and five filed follow-up issues for Opgroeien, AVIQ, Iriscare, Ostbelgien, and ECB HFCS, without adding placeholder facts.

Source pin and fact scope

Official SFPD artifact:

• URL: https://www.sfpd.fgov.be/files/3432/fr_stat_2502.pdf
• SHA-256: 0d6173e71a0e9c2cd220cd024a5b5fecbb6ca79f8b791cbd2b3368e7f8412106
• size: 2,319,705 bytes
• printed page 22, table 2.2: 2,435,457 employee and/or self-employed pension beneficiaries and EUR 3,759,582,728.06 monthly expenditure;
• printed page 36, table 2.4.1: 117,650 GRAPA beneficiaries and EUR 86,398,449.47 monthly expenditure.

All four facts are February 2025 observation assertions with administrative provenance, Belgian country scope, exact publisher periods, and full source-cell lineage. The pension beneficiary snapshot is explicitly dated 1 February 2025. The pension total is narrowed to the employee and/or self-employed regimes actually covered by table 2.2.

An authenticated read-only fetch from the ledger-raw bucket returned exactly 2,319,705 bytes with the pinned SHA-256. No R2 object was uploaded or mutated.

No aging, period alignment, reconciliation, imputation, take-up mechanics, target profile, model binding, solver construction, PolicyEngine-computed value, or Axiom concept is included.

Validation

• validate-package sfpd-legal-pension-caseload-2025 --year 2025: PASS, 4 record sets/rows/measures and zero errors/warnings;
• source suite: PASS, 13,644 full-document source cells, 4 facts, 100% lineage, zero agent-acceptance errors;
• package bundle and consumer artifact build/load: PASS, 4 rows;
• parser/SFPD plus the five existing packages exposed by the first CI run: 27 passed after restoring the original default grammar;
• facts-only and consumer tests: 33 passed;
• full 151-package merged-bundle contract: PASS in 14m11s with 171,855 facts, 43 sources, 146 source tables, zero aggregate duplicate keys, and the one pre-existing semantic-duplicate warning;
• Ruff and git diff --check: PASS;
• ledger-source-fidelity: PASS;
• ledger-boundary: PASS.

The full bundle run exposed stale period/entity histograms for these four replacement facts. The corrected goldens move four facts from calendar year 2025 to February 2025 and two expenditure facts from person to government. No fact value, selector, or source-package semantic changed in that correction.

Follow-ups and governance

The regional child-benefit and HFCS sources require native exports or official publisher responses. Their deterministic retrieval instructions are in FETCH-MANIFEST-BELGIUM-PUBLIC-FACTS.json; no values were transcribed. Follow-up issues are #214--#218.

The literal ledger-source-ingestor.allowed_paths list omits several paths this task explicitly requires (PROGRESS.md, db/data/**, the root handoff, issue drafts, and the pre-existing Belgium test). This PR makes no contract, schema, core, model, or consumer-owned behavior change; maintainer acceptance or a registry clarification remains required for that path inconsistency.

Exact-head Fable adjudication at c4969e15136b9eba1ebedf6c51aa5938acf697ee: APPROVE, no critical/high findings and no blocking code finding. This remains a draft pending final-head CI and the disclosed path-registry decision. Nothing is merged.

Refs #69