Build the surplus/need matching algorithm

Implement a matching algorithm that pairs food surplus postings with nearby organizations that need them. The algorithm should:

1. Accept a list of surplus items (type, quantity, expiration date, location) and a list of needs (type, quantity needed, location, capacity)
2. Score matches based on: distance (closer = better), expiration urgency (sooner = higher priority), quantity fit (minimize partial matches)
3. Return ranked match suggestions with a confidence score
4. Handle edge cases: no matches available, expired items, over-capacity

Input/output should be typed TypeScript interfaces. Include unit tests for the scoring logic.