shrink-my-file.txt
This file has grown to <n> lines and I've lost the thread: <paste>

Propose a split. For each new file: the name, what moves into it, and
what it exports. Show me the plan as a list — no code yet.

Prefer the fewest files that fix the problem. If you think it should
stay as one file, say that instead and tell me why.

Ask whether it should be split at all. Models will happily produce eight files where two would do, and a maze of tiny files is harder to hold in your head than one long one.