Carry the level everywhere a position is drawn, and gate it per occurrence

plugins/geenforce/api/routes.py

@@ -1223,6 +1223,9 @@ def list_reports():
             'location': known.get('location'),
             'mapx': known.get('mapx'),
             'mapy': known.get('mapy'),
+            # Coordinates are pixels of ONE level (ADR-017), so the level goes
+            # with them or the hover preview has nothing to draw on.
+            'levelid': known.get('levelid'),
             'machinenumber': known.get('machinenumber'),
             'machineassetid': known.get('machineassetid'),
             'machinepluginid': known.get('machinepluginid'),