working is the agent's cursor: one range, where it is about to write. It is shown in the strip
and as a box on the grid, never listed or logged, and gone on its own: replaced by the next
working call, cleared by any commit or any other highlight, and by Esc. finding and question
are things the agent wants the user to look at; they accumulate as walks and stay until the user
dismisses them.
What a highlight is for: the vocabulary of the MCP
highlighttool.