feat: increase landmark emoji size for better visibility

Increase landmark size multiplier from 2.5x to 4.0x, making scenery
emojis more prominent and visually similar in scale to the player
avatar (96px default vs 70px player).

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

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

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

@@ -267,7 +267,7 @@ export function SteamTrainJourney({ momentum, trainPosition, pressure, elapsedTi
             x={pos.x}
             y={pos.y}
             textAnchor="middle"
-            fontSize={(landmarks[index]?.size || 24) * 2.5}
+            fontSize={(landmarks[index]?.size || 24) * 4.0}
             style={{
               pointerEvents: 'none',
               opacity: 0.7,