improvements-NetPulseEngine.txt

- Remove the video ID from the user's watch history when the video is deleted.
- Optimize the retrieval of the watch history by directly fetching it without recalculating aggregates each time. It can be done by pre-existing functionalities of addition and removal of videos in the watch history through the video controller.
- Restrict the ability to add comments to videos that are unpublished.
- Implement a check to ensure a video is not added to a playlist multiple times.
- Enhance the response format when fetching subscribed channels.
- Ensure that the Like document associted with deleted videos, tweets, and comments are removed from the Like collections to make sure a deleted resource is not liked by the user.