🎨 Palette: Add keyboard hint and ARIA live region to game score

[EiJackGH]

💡 What:
Added aria-live="polite" and aria-atomic="true" to the score counter in the Mario Game. Additionally, an on-screen text hint was added below the score to explicitly inform players of the keyboard controls ("Press Space or Up Arrow to jump"). Also cleaned up requirements.txt to remove venv which was causing pip install failures.

🎯 Why:
Dynamically updating text like a score counter needs ARIA attributes to be properly announced by screen readers without interrupting the user. The game also entirely lacked visible instructions for how to play; adding a persistent hint lowers the barrier to entry and cognitive load for new users.

📸 Before/After:
Before:
Score counter was visually updated but silent to assistive technologies. No keyboard controls were shown.

After:
Score updates are announced. A clear textual hint is positioned visibly at the top left.

♿ Accessibility:

• Applied aria-live="polite" to #score so that screen readers announce the changing number as the game progresses.
• Added explicit keyboard control hints so users aren't left guessing which keys trigger actions.

---

PR created automatically by Jules for task 15070201797901690005 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.

[github-actions]

Stale pull request message