send the map selection to change detection and show the modified class

The comparison hook runs before the selection state is declared in App, so the
selection is read through a getter at the moment the run starts rather than
captured at render. The panel gains the modified count, which until now was
folded into removed plus added.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/App.tsx

@@ -305,6 +305,8 @@ function WorkbenchApp({ username, accessMode, loggingOut, onLogout }: WorkbenchA
     selectedProjectId,
     availableVectorDatasets,
     loadDatasetJobs,
+    // Bind the comparison to whatever the operator has selected on the map.
+    getSelection: () => ({ bbox: mapSelectionBbox ?? null, areaId: selectedMapAreaId ?? null }),
   })
   const {
     qaCandidateDatasetId,