fix(TASK-29): mesh mobile gutters — add 12px padding

Mobile mesh view had padding: 0 causing glass cards to go edge-to-edge.
Added 12px padding for consistent gutters.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/views/Mesh.vue

@@ -1412,7 +1412,7 @@ function truncatePubkey(hex: string | null): string {
 @media (max-width: 768px) {
   .mesh-view {
     height: auto;
-    padding: 0;
+    padding: 12px;
   }
 
   .mesh-columns {