All changes were tested for performance regressions. None of the included changes were affected. However, the code that uses `whereIn('category_id', Category::select('id')->where('movie_meta', '=', 1)` saw a ~10% performance loss so should not be changed.
Use eager loading where necessary and add a few indexes. The existing index on private_messages for sender_id and read was probably a typo and intended for receiver_id. The first 3 tables indexes are added to are used for queries ran on every page load: namely the new pm, new notification and warnings indicator in the navbar. Additionally, another index on genre_movie proved useful for finding all the genres when given a movie id. Perhaps, another index for finding all movies within a genre would be good as well, but will leave that for a future optimization if deemed necessary.
