The translate.toil.cc relay that backs the yandex provider is currently
unavailable. Introduce a `disabled` flag on TranslationProvider and
filter disabled providers out of both `getTranslators()` and
`getTranslator()` so the settings panel, translator popup, and the
fallback logic in `useTranslator` all agree the provider doesn't exist —
no per-callsite changes needed. Flip the flag back (or delete the line)
on `yandexProvider` to re-enable once the upstream is healthy.
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Huang Xin