This commit introduces a new test file `tests/utils/video-timestamps.test.mjs`
providing comprehensive unit tests for the functions in `js/utils/videoTimestamps.js`.
The tests cover:
- `getVideoRootIdentifier`: extracting root IDs with fallback logic.
- `applyRootTimestampToVideosMap`: synchronizing timestamps across a map of videos.
- `syncActiveVideoRootTimestamp`: state updates, timestamp normalization, and modal interactions.
These tests help ensure the reliability of video timestamp handling and prevent regressions.
Co-authored-by: PR0M3TH3AN <[email protected]>
