🎨 Palette: Add accessible instructions and dynamic score to Mario game

[EiJackGH]

💡 What: Added explicit keyboard instructions ("Press Space or Up Arrow to jump") to the Mario game and made the score accessible to screen readers using aria-live="polite" and aria-atomic="true".

🎯 Why: Users had to discover the jump controls via trial and error. The visual instructions make the controls immediately clear, while the aria-live attributes ensure visually impaired users using screen readers hear score updates dynamically.

♿ Accessibility: Added aria-live="polite" and aria-atomic="true" to the #score element for screen reader support.

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PR created automatically by Jules for task 13448722299501300173 started by @EiJackGH

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