Two new OpenAI STT models, Spanish routing moves to AssemblyAI, and the API contract is corrected to match the router

Status: available. The catalog publishes openai:gpt-transcribe and openai:gpt-live-transcribe as separate candidates, Spanish speech-to-text now routes to AssemblyAI Universal-3.5 Pro on its own measured numbers, and several OpenAPI descriptions are corrected where they described behavior the router never had. New published router ids: openai:gpt-transcribe (buffered) and openai:gpt-live-transcribe (streaming) are now separate speech-to-text candidates rather than one combined board row, and xai:grok-voice-think-fast-2.0 is published.