🎨 Palette: Improved game start experience and UI polish

[aidasofialily-cmd]

💡 What

This PR adds a more polished game start sequence to SPEED CLICKER. It introduces a "Press any key to start" prompt followed by an animated "3... 2... 1... GO!" countdown. Additionally, it refactors the UI update logic in the main loop to be more efficient and consistent.

🎯 Why

Starting the game immediately after execution can be jarring, especially for new players or when the game is in hard mode. The new sequence provides a clear transition from instruction-reading to active gameplay.

📸 Before/After

• Before: Game starts immediately upon execution, printing scores as the timer ticks.
• After: Game waits for a keypress, then displays a 1-second interval countdown (3, 2, 1) before shouting "GO!" and starting the score tracking.

♿ Accessibility

• Provides a predictable start mechanism.
• Includes a tcflush call after the countdown to ensure that frantic keypresses during the animation don't result in accidental game actions, ensuring the game starts only when the user is ready.
• Maintains high-contrast ANSI colors for status indicators.

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PR created automatically by Jules for task 4209051203107821340 started by @aidasofialily-cmd

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