Pre-rendered HTML of the reference's surrounding inline context
(the parent inline token if available, else the reference token
itself). Computed once at index time and stored here so the
Backlinks panel can render without retaining the original
markdown-it Token trees. Used directly as referenceHtmls by
getNoteBacklinks / getTagBacklinks.
OptionalkindFor 'wikilink' / 'link' references: the resolved file path
(relative to the notebook root) of the target note. For 'tag'
references: empty string — the tag identity is in text.
OptionalsourceSource line (zero-based, into the referrer note's markdown) where
this reference's surrounding paragraph starts — taken from the
parent inline token's .map[0], falling back to the reference
token's own .map[0]. Used by the Backlinks panel to build
click-through #L<n> URI fragments. Undefined if the parser
didn't carry source-map info on the token.
The id of the referenced element