- register the provider in provider_endpoints_support.json and claim
tests/unit/llms/gradium in the llms-providers shard, so the provider
documentation and CI/shard coverage gates see it
- rework the transformation to build its params and request body
functionally rather than by mutation, so it clears the type-discipline
rules; the suppressions that remain are the signatures
BaseTextToSpeechConfig fixes and the dicts its return types require
- get_complete_url now tolerates an api_base that already ends in /api.
Gradium documents its regional bases that way
(https://eu.api.gradium.ai/api), and pasting one produced
/api/api/post/speech/tts.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>