Each project folder keeps its own plan
A chat working in another folder plans in that folder, and opening a folder shows its own plan instead of the last folder's.
A project's plan lists the steps for the whole folder. Bandicot used to keep one plan for the folder open in the window, so a background chat working in a different folder edited that plan and saved it into its own folder.
Now every folder has its own plan. A background chat reads and updates the plan of the folder it works in, helpers tick off steps on their parent's folder, and opening another folder in the window shows that folder's plan.