Filter GET /v1/voices by type, locale, gender, and model

GET /v1/voices now takes four optional query filters — type (personal or shared), locale (BCP-47, prefix-matched), gender, and model — applied before pagination so pages stay full. For example, ?type=personal&locale=en&model=simba-3.2 returns only English cloned voices that support Simba 3.2.

Pagination is unchanged and still opt-in (limit plus cursor, max page size 200), and large personal voice libraries that previously risked a slow response now list reliably.

The Build changelog has the full filter table.