How to point out a novel conceptualization in a foundations chapter?
Perhaps the best place to announce this would be in the introduction itself. If this novel conceptualization is part of the aims of the thesis -or can be linked to them in some way-, then the aims section would be a good place to say in which chapter the conceptualization is formally presented (perhaps Chapter 3, after the foundations chapter?)

At the end of the Introduction, it is customary in many fields to announce the thesis structure: in Chapter 2 we will be doing this and that, in Chapter 3... etc. I feel a novel conceptualization would also need to be indicated here.

Disclaimer: I have not yet defended my PhD (on the way to it, almost there), so I would appreciate any guidance other, more seasoned, academics could give both of us!