I use Gemini-cli (free 2.5 pro for an undetermined time before it self-lobotomises and switches to lite) to keep the specs up to date.

The actual tasks are stored in Github issues, which Claude (and sometimes Gemini when it feels like it) can access using the `gh` CLI tool.

But it's all just project management, if what the code says drifts from what's in the specs (for any reason), one of them has to change.

Claude does exactly what the documentation says, it doesn't evaluate the fact that the code is completely different and adapt - like a human would.