Geometry chunking parameters (v13+). Grouping is a WRITE-side layout
policy: readers only trust the directory, so these can change without a
format bump. Cell size mirrors the renderer's spatial bucketing default
but is deliberately independent — the renderer re-buckets on load.
Geometry chunking parameters (v13+). Grouping is a WRITE-side layout policy: readers only trust the directory, so these can change without a format bump. Cell size mirrors the renderer's spatial bucketing default but is deliberately independent — the renderer re-buckets on load.