Allow chapters to be marked as endings. This would allow whole stories to be advertised as "completed" by checking for ending chapters. It could also be utilised to prevent children being added to a chapter by other users where they otherwise freely could, i.e. on public stories. This could just be implemented as a toggle in the edit chapter interface. Chapters that are marked as endings can't have children added to them, and if a chapter has children, it can't be marked as an ending, much like how the delete option works. The completion of stories could be determined by checking that every chapter either has one or more children or is marked as an ending. Possible issues include exploiting this as control over adding chapters where the creator otherwise wouldn't have authority. For example, while you're writing a branch in a public story, you could mark every chapter as an ending when you publish it, then unmark it immediately before you add the next chapter, so that nobody else can add chapters to your branch in the meantime. However, this behaviour might be desired - I can see both sides. An alternative is to make this feature purely non-functional, i.e. ending chapters are displayed as such but children can still be added to them.
Yeah definitely a case where I can see both sides. Personally, I do think authors should have complete control over their chapters and prevent other authors from adding as they see fit, even if it's a public story. But I can also see how one could argue that this goes against the spirit of a public story and if you write for one you just have to accept this.
