Implement /api/getDistributions endpoint

## Description
Implement the \`/api/getDistributions\` Pages Function endpoint.

- Call vm-sdk \`getDistributions()\`
- Store result in KV with daily refresh (distributions change infrequently)
- No query parameters required
- **Returns**: distribution list

## Files
- Create \`functions/api/getDistributions.ts\`

## Roadmap
Task 2.14