Link picker now shows both outgoing [[links]] and backlinks in
a unified list with section headers. Backlinks follow by entity
ID directly, outgoing links resolve by text. Navigating into a
backlink works the same as following an outgoing link — pushes
to nav stack, esc pops back.
Press [ in detail view to open link picker showing all [[links]]
in the current entry. Enter follows a link, resolving by title
then body substring. Navigation history stack enables esc to pop
back through followed links before returning to list.
Adds Store.ResolveLink() for non-transactional link resolution
from the TUI layer.
lerko