- fixes#335: on transient 503/502/504, wait for short cooldown (up to
5s) before falling to next combo model, giving the provider a chance
to recover rather than immediately skipping it
- fixes#334: when all combo models have no active credentials, return
503 (Service Unavailable) instead of 406 (Not Acceptable), which is
more accurate and retriable by clients
Gemini API requires enum properties to have an explicit type:"string"
declaration. Without it, tool calls with enum parameters return 400
Bad Request. Fixes#359.
Anurag Saxena