Four hero compositions (A: pinned left rail / B: right user rail /
C: short banner / D: stacked banners) for the 1200x450 home hero area,
with A marked as the confirmed direction. Referenced by
openspec/changes/pin-home-category-menu/proposal.md.
Home hero becomes a 450px flex row with a pinned 240x450 category rail
(ShellCategoryMenu `pinned` mode) left of the 960px center-cropped
carousel; hovering a top-level category expands the mega-menu over the
carousel. The header no longer collapses on scroll, and its category
dropdown is now hover-only on non-home pages.
OpenSpec change: openspec/changes/pin-home-category-menu
BREAKING CHANGE: the header logo/search/cart bar no longer auto-hides
past 200px of scroll, and the home page no longer shows the header
category dropdown (it is pinned in the hero row instead).
james