make selection box use the selection or deconstruct color to indicate the mode

src/ui/WorldRenderer.cpp

@@ -1028,7 +1028,17 @@ void WorldRenderer::drawOverlays(QPainter& painter, const WorldCoordinates& coor
                         std::max(frame.boxStartTile.y(), frame.boxCurrentTile.y()) + 1);
         const QRectF selRect(coordinates.tileToWidget(tl),
                              coordinates.tileToWidget(br));
-        painter.setPen(QPen(m_visuals.overlays.selectionRect, 1));
+        // In deconstruct mode the box marks buildings for demolition, so it is
+        // drawn in the deconstruct red instead of the selection color; the
+        // tint's alpha governs only the fills it tints, never this outline
+        // (REQ-UI-MULTI-SELECT, REQ-BLD-DECONSTRUCT-BOX).
+        QColor rectColor = m_visuals.overlays.selectedOutline;
+        if (frame.buildMode.isDeconstructMode())
+        {
+            rectColor = m_visuals.overlays.deconstructTint;
+            rectColor.setAlpha(255);
+        }
+        painter.setPen(QPen(rectColor, 1));
         painter.setBrush(Qt::NoBrush);
         painter.drawRect(selRect);
     }