It is a positive that your work has already gone through peer review and is archived.
Yes, cite the previous articles (and retain the original citations from those articles). I would also discuss it in your intro chapter. You will probably have a subsection of the intro called "organization of the thesis". You can have some structure like:
Para one (list and describe the chapters in content, organization. Show a heirarchical structure and a reason for the ordering.)
Para two: Chapters 4, 5 and 7 are original work from this thesis research which were successfully published during the study. (citations). Chapters 6 and 8 are intended to be reworked and published in the future as stand-alone journal articles. Chapters 1 and 2 include synthesized content from the published research reports as well as expanded detail for this thesis. Chapter 3 is a synthesis of issue X of the lab work from articles corresponding to chapters 4, 5, and 6. It is intended to be published as a standalone article in a journal contentrating on issue X
I would go ahead and do some light editing to make the thing more integrated. For example in experimental work, the methods sections for the lab work will have a fair amount of partial duplication. Separating that out to a chapter 2 on "methods" can be useful. Same issue for the intro sections, excise them and combine into a more integrated/expanded section within the Intro chapter that has lit review and motivation.
You may, may not have other reasons to reorganize some of the meat of the content. I would not strain to do so, just do so if it makes editorial sense, not through some desire to change things for appearance.
This is also a good chance to add some expanded content that you feel is helpful but were unable to put into terse journal articles. E.g. details/advice on methods, apparatus, safety. Work that was non-notable for an article (e.g. a computer-based calculation that agrees with earlier direct methods, properties experiments that showed no change in output but may be useful in the future for example in comparison to systems with more interesting results, more detailed simulations, verification of terse proofs/derivations in supporting papers, etc. You should have a little bit the attitude that this thesis may be looked at by follow-on students, postdocs, or even your PI when doing followon work. It can be a helpful training document. This is a bit of a different issue than the archived literature (which serves that function also, but tends to be more terse.)
Also, it is just a chance to record things that you don't want "lost". I am an advocate of "publish everything", but still we have to live with the reality of terseness in normal science articles. Best is to find some way to get every finding, idea into regular journal articles. But the thesis is a sort of "half a loaf" versus just never getting the content recorded at all. The rationale for getting content published is that it prevents rework (which happens too much, see the E Bright Wilson book on research.)
IANAL but I think it is extremely unlikely that journals will have an issue with the republication of content (even graphs and the like) within a student thesis. Or the converse, when the content was in the thesis first.
Nor are your actions unethical. (I disagree with the surfeit of caution in the Buffy reply.) It is very normal in the sciences for a thesis to be a collection of papers. Not the European explicit sandwich. But a lightly edited smorgasbord, sure. Nobody is surprised, bewildered or aghast at this. It is a positive that you already got papers done.