LIVE_PREVIEW_LAYOUT_COOKIE_PREFIX

const LIVE_PREVIEW_LAYOUT_COOKIE_PREFIX: "vex-live-preview-layout:" = "vex-live-preview-layout:"

Defined in: packages/core/src/livePreview/constants.ts:56

Prefix of the per-collection/global cookie remembering how wide the admin panel’s form column was last dragged — vex-live-preview-layout:<slug>, holding the form panel’s percentage of the split.

A cookie, not react-resizable-panels’ own autoSaveId (localStorage): localStorage is unreadable on the server, so the split would always render at DEFAULT_LIVE_PREVIEW_FORM_PANEL_SIZE and then jump to the saved width after hydration — the same first-paint shift the open/closed cookie exists to avoid.