Keep story side actions visible while reading long articles

[samuelclay]

Good idea. I added this as a preference in the preferences dialog, next to the existing story side options settings. It shows up when story buttons are set to the right side. It defaults to on becuase it’s a very good idea, but this way people can revert it to get the old behavior.

When enabled, the story action buttons use native sticky positioning so they stay visible near the bottom while reading longer stories. For short stories, the story gets enough minimum height to fit the action list cleanly. I also cleaned up some other behavior around the minimum height of stories to fit the story actions.

Let me know how that feels! It was a tricky build.