Fix timezone display - convert UTC timestamps to local time

Database stores UTC without 'Z' suffix, causing JS to interpret as local.
Now appends 'Z' to indicate UTC before converting to local time.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cj-vana

src/components/NetworkMap.tsx

@@ -184,7 +184,7 @@ export function NetworkMap({ nodes, className = '' }: NetworkMapProps) {
                   {node.last_seen && (
                     <div className="flex justify-between">
                       <span>Last Seen:</span>
-                      <span>{new Date(node.last_seen).toLocaleString()}</span>
+                      <span>{new Date(node.last_seen.endsWith('Z') ? node.last_seen : node.last_seen + 'Z').toLocaleString()}</span>
                     </div>
                   )}
                 </div>