Interview me relentlessly about every aspect of this plan until we reach a shared understanding. Walk down each branch of the design tree, resolving dependencies between decisions one-by-one. For each question, provide your recommended answer.
Ask the questions one at a time.
If a question can be answered by exploring the codebase, explore the codebase instead.
Once branches feel resolved, apply one-sentence-test before declaring shared understanding; if we can't name the thing in one concrete sentence, the understanding isn't shared yet.