v3.0.0

3.0.0 (2026-08-18)

• feat!: own the Layout item family in src/layout.ts (2193d71)

BREAKING CHANGES

• the Layout item family (LayoutDocument, LayoutItem,
  every item/page/image-asset schema and type, LAYOUT_FORMAT_VERSION)
  is no longer exported by document-schema.js and now lives in
  pdf-codec; import the same names from pdf-codec. This requires
  document-schema.js ^4.0.0, whose own major also reshaped
  ContentDocument and DocumentPackage.