🎨 Palette: Add explicit empty state for high score to improve new user onboarding

[EiJackGH]

💡 What: Added an explicit "None yet! Go set a record!" message for when the user has no high score.
🎯 Why: Instead of hiding the UI element when the high score is 0, showing an empty state provides context and encourages engagement for first-time players.
📸 Before/After: Before, no high score UI was shown if score was 0. After, it shows the encouraging text.
♿ Accessibility: Improves cognitive accessibility and onboarding by explicitly clarifying what is expected (setting a record) instead of leaving the space blank.

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PR created automatically by Jules for task 1222778881225144104 started by @EiJackGH

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