I'm doing a similar thing. Recently, I got $100 to spend on books. The first two books I got were A Philosophy of Software Design, and Designing Data-Intensive Applications, because I asked myself, out of all the technical and software engineering related books that I might get, given agentic coding works quite well now, what are the most high impact ones?
And it seemed pretty clear to me that they would have to do with the sort of evergreen, software engineering and architecture concepts that you still need a human to design and think through carefully today, because LLMs don't have the judgment and a high-level view for that, not the specific API surface area or syntax, etc., of particular frameworks, libraries, or languages, which LLMs, IDE completion, and online documentation mostly handle.
Especially since well-designed software systems, with deep and narrow module interface, maintainable and scalable architectures, well chosen underlying technologies, clear data flow, and so on, are all things that can vastly increase the effectiveness of an AI coding agent, because they mean that it needs less context to understand things, can reason more locally, etc.
To be clear, this is not about not understanding the paradigms, capabilities, or affordances of the tech stack you choose, either! The next books I plan to get are things like Modern Operating Systems, Data-Oriented Design, Communicating Sequential Processes, and The Go Programming Language, because low level concepts, too, are things you can direct an LLM to optimize, if you give it the algorithm, but which they won't do themselves very well, and are generally also evergreen and not subsumed in the "platform minutea" described above.
Likewise, stretching your brain with new paradigms — actor oriented, Smalltalk OOP, Haskell FP, Clojure FP, Lisp, etc — gives you new ways to conceptualize and express your algorithms and architectures, and to judge and refine the code your LLM produces, and ideas like BDD, PBT, lightweight formal methods (like model checking), etc, all provide direct tools for modeling your domain, specifying behavior, and testing it far better, which then allow you to use agentic coding tools with more safety or confidence (and a better feedback loop for them) — at the limit almost creating a way to program declaratively in executible specifications, and then convert those to code via LLM, and then test the latter against the former!