Fixed
- Topology sat on "Scanning site topology…" forever on a site whose devices report no neighbours. The page waited for links to appear, and a site with none never produced any, so the spinner stayed up and the scan restarted every few seconds — reading from every online device in the site each time. The scan now ends when it ends, and the page explains why there are no links instead of spinning. Reported on GitHub (#62).
- The devices in such a site are drawn as unconnected nodes with the explanation beside them, rather than a blank canvas.
- Refreshing the map and then leaving the page no longer leaves it polling in the background.