- Drop the invented Refine note; every field is real (D14).
- Ignore a late close event once the shell was reopened or replaced, so
an action that opens the next dialog keeps it open.
- Dialog openers require the page scope; disposing it closes and removes
the shell unless a newer page's dialog is open. Every route change
closes the shared dialog before the next page mounts.
- Clear filters also reports category '' so the page clears the toolbar
category, as the concept does.
- The toolbar requires its scope and falls back to the first sort for an
unknown value; dialog callbacks are validated up front.
Refs #249