What would be the best approach to detailing a slab to ~6″x8″ timber sill beam transition?

Background:  I’m re-building an addition to a circa 1900 house in Zone 6A.  The site has undulating bedrock ~10-30″ below grade. The slab is planned to be at the same elevation as the existing main house timber sill beam.  Aggregate under the new slab will abut the existing brick foundation of the main house. (Note:  the sill beam has no capillary break and rests directly on brick at the top ~2+ feet of the foundation)

Questions:

What would be the best option for the transition where the slab meets the sill beam? Is there a particular expansion joint product the would be best suited? Is there a product that would help the sill beam with drying to the slab side?

I’m concerned about the brick being below grade.  Is there a product or approach that is best?  My inclination is to try to create a capillary break area along the brick foundation with larger fill covered with filter fabric. It seems that this would create a little air space for the brick as well.  Does this make sense?  Is there a better option?

Thanks!