admin cli neighbors command should sort newest to oldest

examples/simple_repeater/MyMesh.cpp

@@ -706,9 +706,24 @@ void MyMesh::formatNeighborsReply(char *reply) {
   char *dp = reply;
 
 #if MAX_NEIGHBOURS
-  for (int i = 0; i < MAX_NEIGHBOURS && dp - reply < 134; i++) {
-    NeighbourInfo *neighbour = &neighbours[i];
-    if (neighbour->heard_timestamp == 0) continue; // skip empty slots
+  // create copy of neighbours list, skipping empty entries so we can sort it separately from main list
+  int16_t neighbours_count = 0;
+  NeighbourInfo* sorted_neighbours[MAX_NEIGHBOURS];
+  for (int i = 0; i < MAX_NEIGHBOURS; i++) {
+    auto neighbour = &neighbours[i];
+    if (neighbour->heard_timestamp > 0) {
+      sorted_neighbours[neighbours_count] = neighbour;
+      neighbours_count++;
+    }
+  }
+
+  // sort neighbours newest to oldest
+  std::sort(sorted_neighbours, sorted_neighbours + neighbours_count, [](const NeighbourInfo* a, const NeighbourInfo* b) {
+    return a->heard_timestamp > b->heard_timestamp; // desc
+  });
+
+  for (int i = 0; i < neighbours_count && dp - reply < 134; i++) {
+    NeighbourInfo *neighbour = sorted_neighbours[i];
 
     // add new line if not first item
     if (i > 0) *dp++ = '\n';