Sprint 20. Adds features/admin/categories/ (model, gateway interface +
local gateway, facade, list/editor pages), mirroring the admin/products
container/facade/service split.
- indented hierarchy view + native HTML5 drag-and-drop reorder
- visibility toggle, item counter, empty state, include-deleted filter
- editor: slug uniqueness validation, translations, SEO fields, breadcrumb
preview, image via existing MediaPickerComponent
- soft delete/restore, blocked when a category has children or items
- draft/publish status + localStorage draft recovery (mirrors Project
Editor autosave) + CanDeactivate unsaved-changes guard
- wired into app.routes.ts (replaces the categories coming-soon placeholder)
- docs/ADMIN.md + docs/BACKEND.md updated with the new gap detail
Not yet done: admin/products' category dropdown still reads from its own
AdminProductsGateway.loadCategories() rather than this gateway (Sprint 21).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
