Add regional availability data

[i-need-token]

Description

Track which regions/data centers each model is available in (us-east, eu-west, etc.) and add a regions field to the model schema.

Why

Data residency requirements (GDPR, HIPAA, etc.) require knowing where model inference happens. This is critical for enterprise and government users.

Suggested Approach

1. Add regions string array field to the model schema in types/model.ts
2. Update scrape scripts to detect regional availability
3. Add a docs/regional-availability.md documentation page

Labels

good first issue, enhancement