keep an auto-recipe building's summary between its cycles

src/ui/selection/BufferedBuildingContent.h

@@ -44,8 +44,9 @@ protected:
         // REQ-BLD-SALVAGE-BAY) or has no recipe or schematic selected yet: the
         // production section is then not shown (REQ-UI-PRODUCTION-PROGRESS).
         bool runsProduction = false;
-        // 0 while an auto-recipe building sits between cycles, when no single recipe
-        // names a cycle time; the progress line then reads "idle".
+        // 0 only when no recipe describes the cycle at all -- an auto-recipe building
+        // that has yet to run one (REQ-UI-RECIPE-SUMMARY). The progress line reads
+        // "idle" whenever no cycle is actually running, whatever this says.
         double durationSeconds = 0.0;
     };