Buat fungsi gradeWebVitals(lcp, inp, cls) yang menerima 3 metrik Core Web Vitals dan return grading overall.

Parameter:

• lcp dalam milidetik (e.g., 2000 = 2 detik)
• inp dalam milidetik
• cls sebagai decimal (e.g., 0.05)

Grading per metrik:

• LCP: good ≤ 2500, poor > 4000, sisanya needs-improvement
• INP: good ≤ 200, poor > 500, sisanya needs-improvement
• CLS: good ≤ 0.1, poor > 0.25, sisanya needs-improvement

Overall grade:

• Semua "good" → return "passed"
• Ada yang "poor" → return "failed"
• Sisanya → return "needs-improvement"

Hint

• Core Web Vitals: LCP (loading), INP (interactivity), CLS (visual stability).
• Good: LCP < 2.5s, INP < 200ms, CLS < 0.1.
• Cek setiap metrik terhadap threshold good/needs improvement/poor.