feat: complete Wallonia land cover and terrain sources

scripts/README.md

@@ -4,22 +4,39 @@ Setup-, import-, demo- en maintenance-scripts voor GeoIntel.
 
 ## WALOUS source provisioning
 
-Run the networked operator only after checking at least 2 GB of archive space
+Run the networked operator only after checking at least 3 GB of archive space
 plus room for the extracted official GeoTIFFs:
 
 ```bash
 python scripts/provision_walous_sources.py \
-  --years 2020 2023 \
+  --years 2018 2020 2023 \
   --destination storage/source-cache/walous
 ```
 
-The command accepts only the hard-coded official SPW 2020/2023 archives,
-streams with a 1 GB per-archive cap, rejects changed content lengths, extracts
+The command accepts only the hard-coded official SPW 2018/2020/2023 archives,
+streams with a 1.25 GB per-archive cap, rejects changed content lengths, extracts
 only the single GeoTIFF by basename, validates the raster contract and writes
 checksums plus `provisioning-report.json`. Existing valid sources are reused;
 `--force` performs a new download. This is an operator acquisition, not an
 application startup task.
 
+## SPW Wallonia terrain source provisioning
+
+The official 1 m MNT is a large operator asset, never an implicit startup
+download. Reserve at least 90 GB temporarily for archive plus extraction and
+run:
+
+```bash
+python scripts/provision_spw_terrain_source.py \
+  --destination storage/source-cache/spw-terrain
+```
+
+The provisioner accepts only the fixed official SPW artifact, enforces a
+30-60 GB archive range and a single safe GeoTIFF member, validates EPSG:3812,
+one band, native 1 m cells and representative elevation samples, writes
+source/archive SHA-256 evidence and removes the archive after successful
+extraction unless `--keep-archive` is supplied.
+
 ## Runtime verification
 
 Inspect interrupted runtime state without changing it: