[Feature] Implement Live Score Tracking and High Score Persistence Using localStorage

The current Pong game UI visually displays the player and AI scores during gameplay (Player: X | AI: Y). However, the scores are not persisted beyond the current session and there's no high score tracking feature implemented.

This issue proposes enhancing the game by:
Tracking player and AI scores live.
Persisting scores using localStorage.
Storing and displaying high scores (per device/browser).

🛠️ Feature Requirements:
✅ Track live game scores for Player and AI.

✅ Save playerScore and aiScore in localStorage after every point.

✅ Load saved scores from localStorage when the game starts.

✅ Track high score:

Maintain the highest score ever reached by the player.

Display the high score on the UI (e.g., beside Player label or below the scoreboard).

✅ Add a “Reset Score” button that:
Resets both scores.
Clears values from localStorage.
Optionally clears the high score.

🎯 UI Integration Suggestions:
Display High Score near the existing "Player: X | AI: Y" label at the top center.
Add a small reset icon/button beside the score to clear/reset local data.
Style the high score label with a unique color or glowing effect (e.g., gold or neon).

✅ Expected Outcome:
Player and AI scores are persisted across page reloads.
High score is tracked and updated automatically.
Players can reset scores manually.
A more engaging and persistent gameplay experience.