Sorry to belabor the question, when you say "before every session", how many "things" do you do in a session? You say you give them a single task, but do you end up chatting back and forth with the agent in that session? I guess I'm unsure how far back the "context" goes in a conversation and if would drift from your directives if the conversation went back and forth too much.
Usually it’s like “implement a worker/class/module for x” (which will act as a model) and when it did that successfully (with tests and such) I commit everything and I continue the session building the GUI, since the GUI requires deep knowledge of the thing it just made.
If I tell it to make the GUI and worker at the same time, it will usually be poorly written with logic in the views rather than in a model, and it will be tested through views while I want dedicated tests for the model