<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

* **New Features**
* Enhanced audio/video detection for MP4 files to better distinguish
audio-only vs. video.

* **Dependencies**
* Added MP4 parsing dependency and updated AI provider libraries
(Anthropic, Google, OpenAI, etc.).

* **Bug Fixes**
  * Tightened authentication state validation for magic-link/OTP flows.
* Stricter space-join validation to reject invalid client
types/versions.
  * Improved transcript entry deduplication and data handling.

* **API**
* Transcript submit payload now requires infos and removes deprecated
url/mimeType fields.
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