Add demo export cleanup tooling

docs/STORAGE_ARCHITECTURE.md

@@ -99,6 +99,20 @@ Mask files are provenance/debug artifacts. QA, map display and GeoJSON output mu
 
 Do not delete originals automatically. Derived outputs may be cleaned through explicit cache management.
 
+Offline demo export artifacts can be inspected and cleaned with:
+
+```bash
+python scripts/cleanup_demo_artifacts.py
+python scripts/cleanup_demo_artifacts.py --keep-latest 3 --apply
+```
+
+The script is dry-run by default, targets only the explicit
+`GeoIntel Demo - Building QA` project unless an exact `--project-name` is
+provided, keeps the newest export artifacts per matching project and refuses to
+delete files outside `STORAGE_ROOT`. It cleans `exports` records/files only; it
+does not remove original uploads, vector features, QA/QC rows, projects, areas,
+tiles, rasters or masks.
+
 ## Model storage
 
 Model artifacts live under: