First phase of the hero canvas editor (see HERO_EDITOR.md).
- settings.model: add hero_layout to PUBLIC_KEYS so the portal receives it
(corrects the design doc — public settings is a whitelist, not getAll();
hero_layout_draft stays admin-only)
- new HeroElement.jsx: renders one layout element by type (text_block,
buttons, moon, badge, image); absolute % positioning with anchor; shared
by the portal now and the editor canvas later
- MoonDot: optional color override for the hero moon element
- Portal.jsx: parse hero_layout (version-checked, try/catch), render elements
sorted by z; fall back to a DEFAULT_LAYOUT built from the current hero so the
page is byte-for-byte unchanged until staff publish their own
No schema change. Verified: default render matches the old hero; publishing a
hero_layout re-renders the portal; the draft key is not exposed publicly; client
builds; no console errors.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
