Buat fungsi classifyService(serviceName) yang menerima nama cloud service dan mengembalikan model layanannya.

Rules (case-insensitive):

• Mengandung "EC2", "VPS", "Droplet", "VM" → "IaaS"
• Mengandung "Vercel", "Heroku", "Railway", "App Engine" → "PaaS"
• Mengandung "Gmail", "Slack", "Notion", "Figma" → "SaaS"
• Selain itu → "Unknown"

Hint

• Cloud services: IaaS (infra), PaaS (platform), SaaS (software).
• EC2/VM = IaaS. Heroku/Lambda = PaaS. Gmail/Slack = SaaS.
• "EC2" → "IaaS", "Lambda" → "PaaS", "Gmail" → "SaaS".