A kludge of prompts, spreadsheets, and Shortcuts (the apple variety) to utilize an LLM as a perpetual language coach regardless of context window limitations.
Actually, the spreadsheets and shorcuts you could use entirely on your own without LLM support. And also actually those spreasheets aren't in the repo at this time; at some point the system will have the schema documented, and at some further point there may be a system for initializing a fresh language coach that can customize the appropriate schema for a learner.
At the moment the system is completely specialized to my Japanese learning program, but I forsee an evolutionary process of making it more and more generic, and more and more self-initializing.