Root cause

• frontend/packages/ui/src/resource-page-common.tsx: header shows directoryItems when homeNavigationItemsis empty.

• frontend/apps/desktop/src/components/edit-nav-header-pane.tsx: popover seeds docNav only from homeDocument.detachedBlocks.navigation.

• So sites using header fallback (no explicit navigation detached block) render nav links in header, but editor menu sees [] and shows only “Add Navigation Item”.

Plan

1. frontend/apps/desktop/src/components/edit-nav-header-pane.tsx

   • import useDirectory, getSiteNavDirectory, packHmId, nanoid, useMemo, useRef.

   • keep current explicit-nav extraction as-is.

   • add directory query for homeId.

   • build fallbackNav: HMNavigationItem[] from getSiteNavDirectory({id: homeId, directory}).

     • text: item.metadata.name || ''

     • link: item.id ? packHmId(item.id) : item.webUrl || ''

     • type: 'Link'

     • id: stable synthetic block id per item key via useRef(new Map()); generate once with nanoid(). Important so drag/reorder/edit state stays stable across renders.

   • choose source:

     • machineNavigation first

     • else explicit publishedNav if non-empty

     • else fallbackNav

   • pass that into EditNavPopover.

2. Tests: add frontend/apps/desktop/src/components/__tests__/edit-nav-header-pane.test.tsx

   • mock EditNavPopover; assert received docNav.

   • cases:

     • no explicit nav + directory items => popover gets fallback items.

     • explicit nav exists => explicit nav wins over directory fallback.

     • machine draft nav exists => machine nav wins over both.

3. Optional small cleanup

   • extract tiny local mapper(s) inside edit-nav-header-pane.tsx for readability only if needed; no new shared module unless duplication grows.

Why this fix

• minimal; desktop-only.

• matches what user currently sees in header.

• preserves existing publish flow: first edit on fallback nav creates explicit navigation block, which is the expected transition from auto-nav to custom-nav.

Unresolved questions

• Should editor fallback mirror only the public header (getSiteNavDirectory default), or should it include editor-visible private children too? My read: mirror public header exactly.