refactor: filter players to display only those with valid positions and recent timestamps for improved clarity

client/src/components/Map3D.jsx

@@ -1297,9 +1297,11 @@ function Scene({ interactionMode, onInteraction }) {
       ))}
 
       {/* Players */}
-      {players.map((player) => (
-        <PlayerMarker key={player.playerID} player={player} />
-      ))}
+      {players
+        .filter((p) => p.position && Date.now() - (p.timestamp || 0) < 30000)
+        .map((player) => (
+          <PlayerMarker key={player.playerID} player={player} />
+        ))}
 
       {/* Camera controls */}
       <OrbitControls