Then for each subsequent conversation I would ask the model to use this file as reference.
The overall idea is the same, but going through an intermediate file allows for manual amendments to the file in case the model consistently forgets some things, it also gives it a bit of an easier time to find information and reason about the codebase in a pre-summarized format.
It's sort of like giving a very rich metadata and index of the codebase to the model instead of dumping the raw data to it.