geo: one tool directory, one unit boundary, per-asset provenance

Geo/tools/ is now every geographic script, with Geo/README.md documenting each
one; the Blender-side builders moved beside their outputs in Art/blender/*/ and
import their helpers from Geo/tools/osm_common.py.

That module gains to_unreal_local() and to_blender_local(): the only place in the
repository that multiplies metres by 100, so a second silent scale cannot be
introduced. block_height_report.py adds height provenance for the block — 3 of
15 buildings have no height data and render at a placeholder 6.4 m.
asset_metadata.py writes and audits <asset>.geo.json sidecars; four now exist
(hero-facade, terrain, street, blockout) and the audit recomputes each centre from
the origin, failing anything that disagrees.

Geo/verification/2026-11-06-elevation.md

@@ -1,9 +1,9 @@
 # Elevation check — Hollywood Blvd block
 
-Measured 2026-11-06 with `Geo/scripts/elevation_probe.py` against the USGS Elevation Point Query Service (3DEP, 1 m seamless DEM, raster id 129943). Raw responses: `Geo/raw/epqs-2026-11-06.json`. Reproduce with:
+Measured 2026-11-06 with `Geo/tools/elevation_probe.py` against the USGS Elevation Point Query Service (3DEP, 1 m seamless DEM, raster id 129943). Raw responses: `Geo/raw/epqs-2026-11-06.json`. Reproduce with:
 
 ```bash
-python3 Geo/scripts/elevation_probe.py Geo/raw/osm-api-map-2026-11-06.osm --workers 5
+python3 Geo/tools/elevation_probe.py Geo/raw/osm-api-map-2026-11-06.osm --workers 5
 ```
 
 Heights are **orthometric, NAVD88**, as published for 3DEP CONUS. They are not ellipsoidal heights and must not be mixed with GPS/ellipsoid values.