Harden Statbel population import compatibility

CHANGELOG.md

@@ -7,6 +7,26 @@
 
 # Changelog
 
+## Sprint 227 Statbel population import compatibility preflight (2026-07-16)
+
+- Added a local, fail-closed preflight for staged official Statbel population
+  and matching statistical-sector archives. It validates exact source
+  identity, bounded ZIP contents, table/geometry schemas, REDEGEO layout,
+  EPSG:31370, situation date, geometry validity, scope coverage, joins and
+  reconciled national/scope totals before a new import is eligible.
+- Replaced the historical sector-prefix municipality assumption with explicit
+  population/geometry municipality-field reconciliation, which supports the
+  2025 REDEGEO municipal-merger contract without weakening identity checks.
+- Accounted for official `ZZZZ` unlocated population separately from map-ready
+  sectors and bounded lossless `make_valid` normalization of reported source
+  topology errors. Both conditions are visible in the evidence manifest.
+- Hardened the existing population operator to retain official source ZIPs,
+  atomically write derived evidence, require a passed manifest for new imports
+  and revalidate source plus derived SHA-256 values immediately before upload.
+- Added negative regression coverage and packaged the preflight in the
+  all-in-one image and release readiness compile gate. No API, migration,
+  automatic import or existing Dataset was changed.
+
 ## Sprint 226 Governed Statbel population edition probe (2026-07-16)
 
 - Extended the explicit read-only source catalog audit with the official