Loading JSON previously called setScene blindly and crashed when
the file held schema-invalid nodes (e.g. items missing `asset`).
The new dialog parses the file, runs validateBuildJson in core,
and surfaces structure counts (site/building/levels/walls/doors/
windows/items/slabs/ceilings/zones/scans), floor area, and a
per-node Schema Details list grouped by type. Import is blocked
when any hard error exists.
Two schema bugs the validator surfaced are fixed here too:
- SiteNode.children is now an id array like every other node
(was a discriminatedUnion of full objects; three readers carried
a string-or-object ternary that's now dropped). migrateNodes
flattens legacy nested-object children on load. Default-scene
seed and photo-to-scene MCP builder updated to pass `building.id`.
- LevelNode.children now includes shelf — the editor allowed it
but the schema didn't. The schema-vs-registry-as-source-of-truth
discussion is captured in plans/editor-node-registry.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
