Legacy/unparsed door nodes can miss schema-defaulted fields (segments, columnRatios, dividerThickness, panelInset/panelDepth …) and crash the door geometry build (EDITOR-AM). `updateDoorMesh` re-applies the Zod defaults once at entry via `DoorNodeSchema.safeParse` (with a drop-bad-segments retry and a full-defaults fallback), so every downstream read sees populated data — including the shaped-top divider path #334 added. Also normalizes schema-valid legacy doors at load in `migrateNodes`, mirroring the existing stair normalizer, so the door panel and window system see defaulted data too.
Reimplemented against main: the original used `segments ?? []` (wrong — legacy doors rendered an empty frame) and missed the #334 `dividerThickness` sites. Verified: `bun run check-types` clean, biome clean on touched files.
