* Add Sarvam LLM provider, update Sarvam STT models, expose usage_info on run detail.
Depends on pipecat PR dograh-hq/pipecat#43 for STT string language support.
Submodule bump will follow after that merges.
* test: cover Sarvam STT language mapping; link Sarvam docs
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Co-authored-by: Sabiha Khan <sabihak89@gmail.com>
