Move cursor one position after accepting a completion

This work is great -- thanks for everything you've built!

I have a use case where I yield completions for different search operators. An example would be searching for a book, and the completion suggestions are things like author or title. But in the prompt that I use these completions, I actually need to specify the operators like author:"<AUTHOR>" or title:(). For author I have to bracket the author's name in quotations, and for title I have to bracket it in curved brackets.

I include these completions: author:"" and title:(). But after accepting one of these completions I would like to automatically move the cursor position back one so that the user can begin directly writing the author name or title. Is this possible?

Start by tracing the completion-acceptance path in prompt-toolkit and how it updates the cursor position after inserting text. Reproduce the issue with completions such as author:"" and title:(), then verify that accepting them leaves the cursor ready to enter the value inside the delimiters.