feat: complete governed Walloon coverage sources

docs/CODEX_EXECUTION_LOG.md

@@ -3652,6 +3652,28 @@ Validation:
 - `cd backend && python -m alembic heads && python -m alembic upgrade head --sql`
 # Codex Execution Log
 
+## Post-V1 national coverage completion: Wallonia (2026-07-22)
+
+- Validated the official WALOUS 2020 and 2023 archives, their EPSG:3812 1 m
+  raster contract, 11 classes, CC BY 4.0 attribution and published edition
+  accuracy. Added a fail-closed operator provisioner with archive-size,
+  extraction, CRS, resolution, class and checksum gates.
+- Added bounded WALOUS persistence through `DatasetService`, semantic hectare
+  metrics, a governed PNG overlay and automatic 2020/2023 temporal-series
+  materialization. The existing temporal API now compares persisted WALOUS
+  raster metrics while keeping object-level change unavailable.
+- Added the queryable legal SPW flood-hazard polygon product and class-aware
+  metrics through the existing official-vector engine.
+- Wired both integrations through Compose, the all-in-one Unraid runner,
+  editable DockerMan template and readiness gate. Added canonical API,
+  persistence, rendering, temporal and runtime-parity regression tests.
+- Revalidated the official Walloon DTM distribution. The whole-region files
+  are too large for implicit startup or per-selection mirroring (about 41 GB
+  at 1 m and 213 GB at 0.5 m), so elevation remains a documented capacity-plan
+  prerequisite instead of a fake operational source.
+- Reprobed the documented MDK WCS endpoints. Strict TLS still fails hostname
+  validation; acquisition remains disabled and no insecure fallback was added.
+
 This file must be updated by Codex after each implementation pass.
 
 ## Format