## Lecture Video (Preview)
### New Features
* Introducing the fourth generation of Lecture Video manifests.
Manifests now include cumulative lecture summaries and local moment
context throughout the video.
* Version 4 manifests provide richer text-only lecture context without
relying on extracted frame images during chat.
* Lecture Video Chat now picks context based on the student's position:
the latest summary up to their furthest watched offset, plus the latest
moment context at or before the current playback position.

### Updates & Improvements
* The Gemini-backed manifest generator will now generate fourth
generation manifests for all Lecture Videos. Use the "Regenerate" button
under Advanced Options to request a regeneration without making other
changes to your assistant configuration.
* Chat requests now send the current playback offset, validated
server-side against the student's unlocked progress.