Run Spike

A run-spike is throwaway code whose only job is to answer one design question. The question decides the shape.

Pick a branch

Identify the question first — from the request, the surrounding code, or by asking:

• "Does this logic / state model hold up?" → LOGIC.md: an interactive terminal app over a pure logic module the user can drive by hand.
• "What should this look like?" → REQUIRED SUB-SKILL: use draft-ui — the UI branch is that skill now: divergent real-HTML variants behind a switcher, a review loop, and a locked ui-brief. UI.md is a pointer.

Picking the wrong branch wastes the whole run-spike. If it's genuinely ambiguous and the user is unreachable, choose by proximity (backend module → logic; page or component → UI) and record the assumption at the top of the run-spike.

Rules for the logic branch