fix: mesh mobile header hidden + DID hover on node names

- Mesh: remove display:flex from .mesh-header CSS that overrode
  Tailwind hidden class, causing title/peers to show on mobile
- Federation: add title={did} on node name for hover tooltip
- Cloud: add title={did} on peer name for hover tooltip
- Both already show node.name when available, DID as fallback

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

neode-ui/src/views/Cloud.vue

@@ -64,7 +64,7 @@
             </svg>
           </div>
           <div class="flex-1 min-w-0">
-            <h3 class="text-lg font-semibold text-white mb-0.5 truncate">{{ peer.name || truncateDid(peer.did) }}</h3>
+            <h3 class="text-lg font-semibold text-white mb-0.5 truncate" :title="peer.did">{{ peer.name || truncateDid(peer.did) }}</h3>
             <p class="text-xs text-white/50 truncate">{{ peer.onion }}</p>
           </div>
           <svg class="w-5 h-5 text-white/30" fill="none" stroke="currentColor" viewBox="0 0 24 24">