Create ZIP code risk score calculator

Write a function that calculates a water quality risk score (0-100) for a given ZIP code based on nearby facility violations. Input: ZIP code string. Output: { score: number, factors: string[], nearbyViolations: number }.

The score should factor in:

• Number of facilities with active violations within 10 miles
• Severity of violations (significant vs. minor)
• Recency of violations (last 12 months weighted higher)

Use the Haversine formula for distance calculations. Write unit tests with at least 3 test cases.