Follow-up to the cherry-picked gateway fix: instead of re-inferring "keyless
mode" from the key env var (wrong for Firecrawl, whose managed-gateway and
self-hosted routes bypass the ring without a key), `_rescue_eligible` asks the
ring vendor's own predicate — `_use_keyless_ring()` for Firecrawl, `use_keyless`
for the others. That covers the persisted `nous` selection the contributor fix
handled AND the legacy never-configured fallback onto a ready gateway, plus
`FIRECRAWL_API_URL`. A ring vendor that actually walked the ring stays
ineligible (its failure means the ring already failed). Docs mention the
gateway route is rescued.
80f76edfaf