I think the clothing capsule is great Astrid. I go on similar sorts of holidays with a similar sort of size capsule, with a couple of exceptions. I tend to do laundry every second day on holiday and summer things dry so quickly. You have at least four days worth here so you will be fine!!
I normally only have one swimsuit - they dry quickly.
The additions I would add (for me) are
- long sleeved loose top (to cover shoulders in the sun)
- exercise gear (shorts or tights and tank and running shoes and cap)
- light cardigan or bolero or denim jacket to throw over dress or shorts and tee in the evening
- one more pair of shoes, I usually go away with four pairs (running shoes/two casual sandals/slides, one dressier pair). I could make do with three pairs though.
Your breton may cover the first and third points, and it sounds like you have the sandals in hand.
Have a wonderful time!!