Add a space after each word when gesture typing

This is a feature that drove me back to the GBoard because I was so used to it - having the keyboard automatically add a space, so that when you need to end a sentence you just press space again to add a period. I do feel it should be should be configurable in the settings but opt-out by default since this is how the majority of existing gesture typing keyboards work and it is not a privacy or data concern.

Thanks for all the hard work you've put into this, and I am excited to keep helping test this!

No files, tests, or entry points are named. Start by locating the Kotlin Android gesture-typing handling and its word-spacing behavior, then check how keyboard settings are represented. Done means gesture-typed words receive the requested automatic spacing and the sentence-ending period behavior, with the opt-out setting and default clarified.

Written by the indexing model from the issue text.