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/README.md

@@ -0,0 +1,83 @@
+# Backlog — showcase hardening
+
+Ordered work packages that take this POC from "good" to **reference showcase**: CIBG
+design-system fidelity, DDD/FP consistency, Storybook as curriculum, and WCAG compliance
+with automated gates. Source: the architecture/CIBG/a11y audit of 2026-07-02 (plan:
+"Showcase hardening").
+
+This backlog **supersedes `docs/SHOWCASE-ROADMAP.md`**.
+
+## Session protocol
+
+- **Switch to Opus first** (`/model opus`) before tackling any WP.
+- **One WP per session.** Read `CLAUDE.md`, this README, the WP file, and the WP's
+  "Read first" list — then execute. Do not start the next WP in the same session.
+- The **Decisions** block in each WP is pre-made — don't relitigate it.
+- A WP ends **GREEN** (below) with its acceptance criteria checked off and its Status
+  updated to `done` (+ commit hash).
+- No WP leaves a lint rule/check disabled without an inline justification comment **and**
+  a cross-reference to the WP that will remove it.
+
+## GREEN (global definition of done)
+
+```bash
+npm run lint && npm run check:tokens && npm test && npm run build && npm run build-storybook
+```
+
+From WP-01 onward, additionally:
+
+```bash
+npm run test-storybook:ci
+```
+
+Backend stays untouched throughout (frontend-only backlog); `cd backend && dotnet test`
+only needs re-running if a WP unexpectedly touches `backend/`.
+
+## Order
+
+Gates land before the work they cover; each lint rule lands in the same WP as the fixes
+for its existing violations, so every WP ends green.
+
+| WP | Title | Phase | Status |
+|----|-------|-------|--------|
+| [WP-01](WP-01-axe-ci-gate.md) | Axe-on-every-story CI gate | 0 · gates | todo |
+| [WP-02](WP-02-check-tokens.md) | Harden `check:tokens` + fix what it catches | 0 · gates | todo |
+| [WP-03](WP-03-contracts-purity.md) | Boundaries I: contracts purity + ApiClient confinement | 0 · gates | todo |
+| [WP-04](WP-04-ui-not-infrastructure.md) | Boundaries II: `ui ↛ infrastructure` + showcase sanction | 0 · gates | todo |
+| [WP-05](WP-05-parse-boundaries.md) | Parse-don't-validate closure + MDX | 1 · FP/DDD | todo |
+| [WP-06](WP-06-typed-async.md) | Generic async template contexts — kill `$any()` | 1 · FP/DDD | todo |
+| [WP-07](WP-07-brief-idioms.md) | Brief on the shared idioms + RemoteData MDX | 1 · FP/DDD | todo |
+| [WP-08](WP-08-store-idiom.md) | One store idiom + machine naming + TEA MDX | 1 · FP/DDD | todo |
+| [WP-09](WP-09-pure-logic.md) | Pure-logic closure: dates + missing command specs | 1 · FP/DDD | todo |
+| [WP-10](WP-10-button-fidelity.md) | CIBG button fidelity | 2 · CIBG | todo |
+| [WP-11](WP-11-markup-fidelity.md) | CIBG markup fidelity: application-link + absent-class triage | 2 · CIBG | todo |
+| [WP-12](WP-12-datablock.md) | CIBG Datablock for application data | 2 · CIBG | todo |
+| [WP-13](WP-13-cibg-gap-register.md) | CIBG-gap register + hygiene + MDX | 2 · CIBG | todo |
+| [WP-14](WP-14-storybook-taxonomy.md) | Storybook taxonomy reorg + Layers MDX | 3 · Storybook | todo |
+| [WP-15](WP-15-missing-stories.md) | Missing stories: shell + brief components | 3 · Storybook | todo |
+| [WP-16](WP-16-component-a11y.md) | Component a11y: description wiring + alert role | 4 · a11y | todo |
+| [WP-17](WP-17-app-a11y.md) | App-level a11y: route focus, template lint, WCAG checklist | 4 · a11y | todo |
+
+Sequencing dependencies (stated in the WPs too): 01 before 10–15 (axe covers story churn);
+03/04 before 05–09 (boundaries stop new violations during refactors); 06 before 07 (typed
+`<app-async>` before brief adopts it); 13 defines the gap-marker format that 11/12 reference
+— if 11/12 run first, they define it and 13 adopts it.
+
+## WP template
+
+```markdown
+# WP-NN — Title
+
+Status: todo | in-progress | done (<commit>)
+Phase: N — name
+
+## Why
+## Read first
+## Decisions (pre-made, don't relitigate)
+## Files
+## Steps
+## Acceptance criteria
+## Verification
+## Out of scope
+## Risks
+```