View playlists without playing them

Tapping a playlist should result in a view displaying the playlist.

That view should then have a "play" and "shuffle" button prominent in the UI. Users should also be able to edit the playlist (remove, add, and reorder files) in this view.

Long-pressing the playlist entry in the list of playlists should also present options to play/shuffle it.

Start by locating the playlist list and the existing play and shuffle actions; the issue names no files, tests, or entry points. Trace how playlist selection currently behaves, then identify the views and state needed for display, editing, and long-press actions. Done means tapping opens an editable playlist view with prominent play and shuffle controls, while long-pressing offers play and shuffle options.

Written by the indexing model from the issue text.