fix(complement-race): use individual player positions for ghost trains

Previously all ghost trains used the local player's trainPosition,
causing them to render at the same location (hidden behind local train).

Now each ghost train uses its own player.position from multiplayer state,
allowing them to be visible at different positions on the track.

Also added logging to show ghost train positions for debugging.

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

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

apps/web/src/app/arcade/complement-race/components/RaceTrack/GhostTrain.tsx

@@ -47,10 +47,10 @@ export function GhostTrain({ player, trainPosition, trackGenerator, pathRef }: G
   const hasLoggedRef = useRef(false)
   useEffect(() => {
     if (!hasLoggedRef.current && trainTransform.opacity > 0) {
-      console.log('[GhostTrain] rendering:', player.name)
+      console.log('[GhostTrain] rendering:', player.name, 'at position:', trainPosition.toFixed(1))
       hasLoggedRef.current = true
     }
-  }, [trainTransform.opacity, player.name])
+  }, [trainTransform.opacity, player.name, trainPosition])
 
   // Don't render if position data isn't ready
   if (trainTransform.opacity === 0) {

apps/web/src/app/arcade/complement-race/components/RaceTrack/SteamTrainJourney.tsx

@@ -217,7 +217,13 @@ export function SteamTrainJourney({
   // Log only when otherPlayers count changes
   useEffect(() => {
     console.log('[SteamTrainJourney] otherPlayers count:', otherPlayers.length)
-  }, [otherPlayers.length])
+    if (otherPlayers.length > 0) {
+      console.log(
+        '[SteamTrainJourney] ghost positions:',
+        otherPlayers.map((p) => `${p.name}: ${p.position.toFixed(1)}`).join(', ')
+      )
+    }
+  }, [otherPlayers.length, otherPlayers])
 
   if (!trackData) return null
 
@@ -285,7 +291,7 @@ export function SteamTrainJourney({
           <GhostTrain
             key={player.id}
             player={player}
-            trainPosition={trainPosition} // For now, use same position calculation
+            trainPosition={player.position} // Use each player's individual position
             trackGenerator={trackGenerator}
             pathRef={pathRef}
           />