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, waiting for feedback on each question before continuing. Asking multiple questions at once is bewildering.

If a question can be answered by exploring the codebase, explore the codebase instead — prefer a subagent so the exploration doesn't clutter this conversation.

Track the design tree

Keep a running outline of the branches so a long session doesn't lose its place when context compacts. Maintain a throwaway .grill-tree.md at the repo root: one line per branch with its status — resolved (✓) or pending — updated as you settle old branches and discover new ones. It doubles as the progress signal: when the user wonders how far along they are, the outline answers without a fake "question N of M".

.grill-tree.md is scratch state, not a deliverable. Add it to .gitignore, and delete it when grilling concludes — by then every settled decision already lives in CONTEXT.md, DESIGN.md, or an ADR, and any high-level branch you deferred rather than resolved has moved to ROADMAP.md to seed a future PRD.

Prototype UI decisions, don't describe them

When a question is spatial — layout, control placement, flow, visual hierarchy, modal-vs-page — text is a poor medium. Generate a minimal throwaway HTML mockup with 2+ variants side by side and let the user react. Delegate the file to a sub-agent so the grilling thread stays focused, then resume with one question: "which variant?" For a richer interactive comparison, hand off to prototype.

Capture the choice before deleting the mockup: the settled convention goes in DESIGN.md ("primary actions live in a sticky bottom bar"), like any resolved term; if the choice was a real trade-off worth an ADR, record the why there — and paste a screenshot or the variant markup into it first, so the rejected options survive the mockup's deletion. Then delete the mockup.