chore: changeset for page regions/properties optional

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

.changeset/studio-page-regions-properties-optional.md

@@ -0,0 +1,15 @@
+---
+"@objectstack/spec": patch
+---
+
+fix(spec): make page `regions` and component `properties` optional
+
+`PageSchema.regions` and `PageComponentSchema.properties` were required, which
+made it impossible to create record/home/app pages in the Studio editor: the
+New Page form has no region editor, and the create-form seeds a record page's
+default layout from `buildDefaultPageSchema`, whose nodes carry props at the top
+level — so every seeded block tripped `regions.N.components.M.properties:
+expected record`. Both are now `.optional().default(...)`; an empty full page
+falls back to the synthesized default layout, slotted pages compose via `slots`,
+list pages ignore regions, and prop-less components (record:activity,
+element:divider) no longer need `properties: {}`.