docs: replace SHOWCASE-ROADMAP.md with docs/backlog/ (17 WPs)

Turns the prior roadmap sketch into ordered, gated work packages (enforcement
gates, FP/DDD consistency, CIBG fidelity, Storybook curriculum, a11y) from the
2026-07-02 showcase-hardening audit.

docs/backlog/WP-14-storybook-taxonomy.md

@@ -0,0 +1,79 @@
+# WP-14 — Storybook taxonomy reorg + Layers MDX
+
+Status: todo
+Phase: 3 — Storybook as curriculum
+
+## Why
+
+49 stories sit in a flat `Atoms/Molecules/Organisms/Templates/Layout` scheme with domain
+outliers (`Registratie/…` wizards, one stray `Shared UI/Status Badge`). The sidebar
+should tell the repo's actual story: a reusable design system on one side, domain
+contexts on the other — the DDD seam made visible. The sidebar becomes the curriculum's
+table of contents.
+
+## Read first
+
+- `.storybook/preview.ts`, `.storybook/main.ts`
+- `src/docs/*.mdx` (three existing Foundations pages)
+- `CLAUDE.md` naming rule (shared = English, domain = Dutch)
+
+## Decisions (pre-made, don't relitigate)
+
+Sidebar scheme (respects the English/Dutch seam):
+
+```
+Foundations/            ← MDX curriculum (all concept pages)
+Design System/
+  Atoms/… Molecules/… Organisms/… Templates/…   ← everything in shared/ui + shared/layout
+Domein/
+  Registratie/… Herregistratie/… Brief/… Auth/… ← everything in a context's ui/
+```
+
+- Rule: **a component in a context folder gets a `Domein/<Context>/` title, full stop**
+  (context organisms like `aanvraag-block` move from `Organisms/` to
+  `Domein/Registratie/`). Component display names stay as authored (the folder tells the
+  context).
+- `Devtools/` (debug-state) files under `Design System/Devtools/`.
+- Order pinned via `parameters.options.storySort`:
+  `['Foundations', 'Design System', ['Atoms','Molecules','Organisms','Templates','Devtools'], 'Domein']`.
+
+## Files
+
+- All `*.stories.ts` `title:` fields (~49, mechanical)
+- `.storybook/preview.ts` (`storySort`)
+- Existing `src/docs/*.mdx` (fix any story references broken by retitling)
+- New `src/docs/layers.mdx` — title `Foundations/Layers & Contexts`
+- `CLAUDE.md` — the story-title convention (one paragraph in §2 or Conventions)
+
+## Steps
+
+1. Retitle all stories per the scheme (fix `Shared UI/Status Badge`).
+2. Add `storySort`; build Storybook and check the sidebar.
+3. `layers.mdx`: 6 contexts, 5 layers, the inward dependency rule, "this is enforced" (link
+   the eslint rules from WP-03/04), the English/Dutch seam — i.e. the sidebar's own
+   rationale, with links into real stories on both sides.
+4. Check every MDX `<Canvas of={…}>`/story import still resolves (build-storybook
+   catches broken refs — do an explicit pass anyway).
+5. Convention into CLAUDE.md.
+
+## Acceptance criteria
+
+- [ ] Sidebar shows exactly Foundations → Design System → Domein with the sub-order
+      pinned.
+- [ ] Zero story titles outside the scheme (grep `title:` and eyeball).
+- [ ] `layers.mdx` renders; existing MDX pages unbroken.
+- [ ] Convention in CLAUDE.md.
+
+## Verification
+
+GREEN + `npm run test-storybook:ci` (the axe run also re-visits every retitled story).
+
+## Out of scope
+
+New component stories (WP-15); the remaining curriculum pages (they ship with their
+invariant-WPs: 05, 07, 08, 13, 17).
+
+## Risks
+
+MDX story references breaking on retitle — `build-storybook` is the catch; fix-forward
+in the same session.