List Voices

List TTS voices available to the current workspace. Every filter accepts repeat-key OR semantics: `?gender=female&gender=neutral&category=narration&source=platform&source=workspace`. Filters combine across fields with AND; within a field, values OR. `language` uses Postgres `?|` (exists-any) against `voices.supported_languages`. Platform voices with NULL `supported_languages` (catalog gaps) are treated as general-use and match every locale filter. User-uploaded / cloned voices with NULL stay excluded — NULL there means "language unknown" pending the clone flow's language detection. Multi-sort: `sort` and `order` are parallel lists. `?sort=uses_count&sort=name&order=desc&order=asc` orders primarily by uses_count DESC, secondarily by name ASC. When `order` is shorter than `sort`, missing entries default per-field: `name=asc, created_at=desc, uses_count=desc`. When `sort` is omitted, list defaults to newest-first (or most-recently-favorited-first if `favorites_only=true`). Every sort path appends `Voice.id ASC` as a deterministic tiebreaker for pagination stability.