Buat fungsi risikoMigration(tipe) yang menentukan tingkat risiko dari jenis migration:

• "add column" atau "add index" → return "low" (additive, aman)
• "rename column" atau "change type" → return "medium" (perlu hati-hati)
• "drop column" atau "drop table" → return "high" (data bisa hilang)
• Selain itu → return "unknown"

Hint

• Additive migration (add) aman. Destructive (drop) berisiko tinggi.
• Add column/index = low. Rename/change type = medium. Drop = high.
• "add column" → "low", "drop table" → "high".