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>
