Reference

`space.cell`

domain: space

The canonical SPACE block — the addressing frame (WHERE) embedded by every spatial record's `space` field. Space is a coordinate ON a fact, never a token IN the schema name: there is no `cell.*` domain. A cell measure carries `{h3,res}`; an entity with a real footprint also carries `geometry`; both may carry `boundary_ref` for administrative rollups. H3 is a reference frame (UN-GGIM), not a data domain. Every located schema's `space` field conforms to this object so `data->'space'->>'h3'` joins are uniform across domains.

Field	Type	Required	Description
`h3`	`string`	✓	H3 cell index (15 hex). Primary spatial key for cell measures; containment cell for entities.
`res`	`integer`	✓	H3 resolution of `h3` — a field, never part of the schema name (same measure at res 7/8/9 is one schema, different rows).
`centroid`	`array<number>`		[lon, lat] of the cell centroid (convenience).
`geometry`	`object`		Optional GeoJSON geometry for entities with a real footprint/line (building polygon, road line). Entities carry geometry + the h3 containment cell; cell measures carry only h3+res.
`boundary_ref`	`string`		Optional resolvable id of the governance boundary (ward/zone/ULB/district) containing this fact — for admin rollups without point-in-polygon at query time.