feat: a repaired hole keeps a fainter band, so a report is not a false accusation

src/plot_host.hpp

@@ -12,7 +12,6 @@
 #include <map>
 #include <memory>
 #include <string>
-#include <utility>
 #include <vector>
 
 namespace udpscope {
@@ -502,7 +501,7 @@ class RowSet {
   /// coloured without anything having to seed them.
   std::map<std::string, plot::u32> signal_colors_;
   /// Reused across frames by `set_invalid_spans()`: see there.
-  std::vector<std::pair<f64, f64>> spans_;
+  std::vector<plot::InvalidSpan> spans_;
   CursorMode cursor_mode_ = CursorMode::Vertical;
   bool cursors_on_ = false;
   bool relative_x_ = false;