#12975: Config Builder: align with existing OpenClaw web UI stack

## Summary - switch the config-builder plan away from Next.js/Tailwind to the same stack as the OpenClaw web UI (`ui/`) - bootstrap `apps/config-builder/` as a workspace package placeholder - add `apps/*` to the pnpm workspace so implementation can start in this branch - implement Phases 0–6 in vertical slices: - schema/browser compatibility spike - explorer scaffold + typed field rendering - persisted sparse config state + JSON5 preview - real-time validation with field/section error UX - wizard mode (7 curated steps) - landing + hash routing + responsive preview drawer + static-host config ## Run in dev mode (for now) ```bash pnpm --filter @openclaw/config-builder dev ``` ## Notes - planning details are maintained in `.local/config-builder-spec.md` - draft PR opened before implementation, per request - this is still a draft; UX iteration is expected before merge ## What is next - UX improvement pass (scheduled for tomorrow), including: - tighter visual hierarchy and spacing - better complex/nested editor affordances - improved field grouping/collapse behavior - polish around validation messaging and action flows - continue strengthening focused UI tests around wizard/explorer interactions