Merge pull request #214 from AdaWorldAPI/claude/cesium-osm-substrate-v1

feat(cesium): osm_pbf D-OSM-1 stub mirroring arcgis_pbf shape (5 unit + 7 doctests; live Q3 Y-flip helper)

Author: AdaWorldAPI

crates/cesium/src/lib.rs

@@ -48,6 +48,7 @@ pub mod tileset;
 pub mod implicit_tiling;
 pub mod khr_gs;
 pub mod arcgis_pbf;
+pub mod osm_pbf;
 pub mod spz;
 pub mod esri_crs;
 pub mod to_cam_soa;