`udpscope-math-symbolic` was the toolbar's math-pane toggle, and that toggle is gone. Nothing
else names it: the census after the change is **five** action icons
(`udpscope-{trigger,cursors,measure,events,resize-rows}-symbolic.svg`) plus the two application
icons, seven bundled.
`udpscope-measure-symbolic` **stays**, and the plan's premise ("both lost their last user") is
wrong for it: `src/ui/preferences.ui` carries it as the Plot preferences page's icon -- a live
user, unrelated to the toggle that introduced it. Deleting it would have shipped a page whose
icon silently fails to resolve (GTK substitutes a placeholder and says nothing), so it stays and
the doc's census names it as the Preferences icon rather than as a toolbar one.
The warning baseline is unchanged: **four**, because the icons' generated GResource blob is
**8613 bytes** against C99's 4095-byte string-literal limit with the five action icons and the
two app icons -- removing one file did not put it back under, and neither figure moved on a
clean build. Measured by touching the two `*.gresource.xml` files and rebuilding, which
regenerates both blobs without one.
Verified: `make test-ui` 14 files; a run with the Preferences dialog opened resolves every icon
(`toolbar icons:` all `(ok)`, zero `Gtk-CRITICAL`, no "not present").
Martino Ferrari
cb866774c6