Option to save context / Automate "recall" to continue project

Tell me if I'm wrong, but based on my experience so far, I always had to create the mentioned functionality myself.

It would be great to have a process that somehow automatically documents the development in a way that is understandable for AI, and can continue it upon request (/continue) even in a completely new context.

What has worked for me so far is that during planning it breaks down the development into phases, and with a phase-index it can clearly see what is done and which one needs to be read when continuing:

phase-index.md phase-01-done-short-description.md phase-02-done-short-description.md

I'm sure there are better methods as well — is there any solution in ag-kit for tracking development or the best way is to create a rule for myself?