qml: Recommend the 'top' OS

We're going to take advantage of the
convention of always putting the recommended OS first in the list, and
append "(Recommended)" to it's description.

This moves the recommendation out of the JSON, and makes the
recommendation durable to filtering.

src/main.qml

@@ -1654,6 +1654,19 @@ ApplicationWindow {
             if (oslist === false)
                 return
 
+            /* As we're filtering the OS list, we need to ensure we present a 'Recommended' OS.
+             * To do this, we exploit a convention of how we build the OS list. By convention,
+             * the preferred OS for a device is listed at the top level of the list, and is at the
+             * lowest index. So..
+             */
+            if (oslist.length != 0) {
+                var candidate = oslist[0]
+
+                if ("description" in candidate && !("subitems" in candidate)) {
+                    candidate["description"] += " (Recommended)"
+                }
+            }
+
             osmodel.remove(0, osmodel.count-2)
             for (var i in oslist) {
                 osmodel.insert(osmodel.count-2, oslist[i])