Buat fungsi calculateAnimationProgress(startTime, currentTime, duration) yang menghitung progress animasi.

• startTime: timestamp awal (ms)
• currentTime: timestamp sekarang (ms)
• duration: durasi total animasi (ms)

Return object:

• progress: angka 0-1 (clamp, tidak boleh lebih dari 1)
• isComplete: boolean — true jika progress >= 1
• elapsedMs: selisih currentTime - startTime

Hint

• requestAnimationFrame menyinkronkan animasi dengan refresh rate browser.
• Progress = (currentTime - startTime) / duration, capped at 1.
• return Math.min((currentTime - startTime) / duration, 1);