Problem: the pending buffer has action-button mappings but no Vim
grammar. You cannot dat to delete a task, cit to change a description,
or ]] to jump to the next category header.
Solution: add textobj.lua with at/it (a task / inner task), aC/iC
(a category / inner category), ]]/[[ (next/prev header), and ]t/[t
(next/prev task). All text objects work in operator-pending and visual
modes; motions work in normal, visual, and operator-pending. Mappings
are configurable via the keymaps table and exposed as <Plug> mappings.