Buat fungsi evaluateAlert(rule, currentValue) yang mengevaluasi apakah alert harus triggered.

rule format: { metric, operator, threshold, severity }

• operator: ">" (greater), "<" (less), ">=" (gte), "<=" (lte)

Return: { triggered: boolean, severity, metric, currentValue, threshold }

Hint

• Alert memicu notifikasi saat metrik melewati threshold.
• Evaluasi rule: currentValue vs threshold, cek operator.
• if (rule.operator === ">" && currentValue > rule.threshold) fire alert.