Verifying metadata-admin designer changes (no backend needed)

The console ships a dev-only gallery that renders every registered metadata designer (packages/app-shell/src/views/metadata-admin/previews/*) with representative sample drafts, in edit mode, with zero backend:

cd apps/console && pnpm exec vite --port <free-port> --strictPort
# open http://localhost:<free-port>/preview-gallery.html
# isolate one designer: /preview-gallery.html?only=flow   (or ?only=dashboard, page, …)

Sample drafts live in apps/console/src/preview-samples.ts (keyed by metadata type: flow, workflow, object, …). Server-driven affordances (e.g. the flow palette's GET /api/v1/automation/actions) fail fetch and fall back to their hardcoded defaults — that IS the offline path, not an error.

Driving it headlessly