Surface the ?scenario= and ?role= dev stand-ins as dropdowns in the existing debug-state devtool, so a demo can flip them with a click instead of editing the URL. scenario.ts/role.ts gain set* setters + exported valid-value lists (reused by the panel, no duplicated source of truth); scenario becomes tab-sticky like role so it survives navigation. Applied via location.reload() since both are read per-request in interceptors. Extends the debug-state eslint exemption to the ui→infrastructure rule (same devtool precedent). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>