- [x] bulk category editing: when on a certain category view, add bulk category editing, such that all channels saved to that category are updated with the new categories set.
- [ ] ui improvement: display the pinned status on category tab titles for pinned categories
- [x] start the terebi player as a new instance explicitly:
    ```sh
    terebi --new-instance
    terebi --new-instance "/path/to/video.mp4"
    terebi --new-instance --url 'https://youtu.be/jNQXAC9IVRw'
    ```