🎨 Palette: Add accessibility and interaction instructions to Mario game

[EiJackGH]

💡 What

• Added a visible on-screen instruction panel explaining the keyboard controls for the game ("Press Space or Up Arrow to jump").
• Added aria-live="polite" and aria-atomic="true" to the dynamic score counter.

🎯 Why

• Without explicit visual instructions, users had to guess which keyboard inputs would trigger an action in the game. Adding explicit instruction text eliminates this friction.
• Previously, screen readers would not dynamically announce the score updates when they changed during gameplay.

📸 Before/After

• Before: A blank game UI with only the score, and custom keyboard events requiring guesswork.
• After: A translucent instruction panel is visible in the top right corner indicating the correct controls.

♿ Accessibility

• Implemented aria-live="polite" on the score component so screen readers announce dynamic point changes as they happen without aggressively interrupting other critical browser announcements.

---

PR created automatically by Jules for task 18315401910550532080 started by @EiJackGH

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.