Merge a layout head with a page head, the page winning on every conflict.
The layout head is the base (brand defaults); the page head is merged on top, so same-key
metas/links (deduped by property/name/rel) and title/description from the page replace
the layout's. This is the hierarchical "layout head + page head" contract of HeadManager.
Parameters
OptionallayoutHead: HeadContext
The layout-provided base head (optional).
OptionalpageHead: HeadContext
The page-provided head (optional, wins on conflict).
Returns HeadContext
The merged head, or whichever side is defined when only one is.
Merge a layout head with a page head, the page winning on every conflict.
The layout head is the base (brand defaults); the page head is merged on top, so same-key metas/links (deduped by
property/name/rel) and title/description from the page replace the layout's. This is the hierarchical "layout head + page head" contract of HeadManager.