feat(ui): liste des cartes cliquable avec thème (F-08)

Composant CardList : charge les cartes via cardsApi.list(), affiche
question + thème, chaque entrée est un lien vers le détail. Gère les
états chargement, vide et erreur (ApiClientError).

src/components/card-list.test.tsx

@@ -0,0 +1,65 @@
+import { render, screen, within } from '@testing-library/react'
+import { describe, expect, it, vi, beforeEach } from 'vitest'
+import { CardList } from './card-list'
+
+vi.mock('@/lib/api-client', () => {
+  class ApiClientErrorMock extends Error {
+    status: number
+    constructor(status: number, name: string, message: string) {
+      super(message)
+      this.name = name
+      this.status = status
+    }
+  }
+  return {
+    ApiClientError: ApiClientErrorMock,
+    cardsApi: {
+      list: vi.fn(),
+    },
+  }
+})
+
+import { cardsApi, ApiClientError } from '@/lib/api-client'
+
+const CARDS = [
+  { id: '1', question: 'Cest quoi un commit ?', response: 'Un snapshot du projet', theme: 'git', tags: [], createdAt: new Date().toISOString(), updatedAt: new Date().toISOString() },
+  { id: '2', question: 'Cest quoi une closure ?', response: 'Une fonction + son scope', theme: 'javascript', tags: [], createdAt: new Date().toISOString(), updatedAt: new Date().toISOString() },
+]
+
+beforeEach(() => {
+  vi.mocked(cardsApi.list).mockReset()
+})
+
+it('affiche le nom de chaque carte', async () => {
+  vi.mocked(cardsApi.list).mockResolvedValue(CARDS)
+  render(<CardList />)
+  const question = await screen.findByText('Cest quoi un commit ?')
+  expect(question).toBeInTheDocument()
+  expect(screen.getByText('Cest quoi une closure ?')).toBeInTheDocument()
+})
+
+it('affiche un lien vers le détail de chaque carte', async () => {
+  vi.mocked(cardsApi.list).mockResolvedValue(CARDS)
+  render(<CardList />)
+  const link = await screen.findByRole('link', { name: /Cest quoi un commit \?/ })
+  expect(link).toHaveAttribute('href', '/cards/1')
+})
+
+it("affiche le thème de chaque carte", async () => {
+  vi.mocked(cardsApi.list).mockResolvedValue(CARDS)
+  render(<CardList />)
+  const item = (await screen.findByText('Cest quoi un commit ?')).closest('li')
+  expect(within(item as HTMLElement).getByText('git')).toBeInTheDocument()
+})
+
+it('affiche un message si aucune carte', async () => {
+  vi.mocked(cardsApi.list).mockResolvedValue([])
+  render(<CardList />)
+  expect(await screen.findByRole('status')).toHaveTextContent('Aucune carte')
+})
+
+it('affiche un message derreur si le chargement échoue', async () => {
+  vi.mocked(cardsApi.list).mockRejectedValue(new ApiClientError(500, 'InternalServerError', 'Boom'))
+  render(<CardList />)
+  expect(await screen.findByRole('alert')).toHaveTextContent('Boom')
+})

src/components/card-list.tsx

@@ -0,0 +1,68 @@
+import Link from 'next/link'
+import { useEffect, useState } from 'react'
+import { ApiClientError, cardsApi } from '@/lib/api-client'
+
+interface ListedCard {
+  id: string
+  question: string
+  theme: string
+}
+
+export function CardList() {
+  const [cards, setCards] = useState<ListedCard[] | null>(null)
+  const [error, setError] = useState<string | null>(null)
+
+  useEffect(() => {
+    let cancelled = false
+    cardsApi
+      .list()
+      .then((data) => {
+        if (!cancelled) {
+          setCards(
+            data.map((card) => ({
+              id: card.id,
+              question: card.question,
+              theme: card.theme,
+            })),
+          )
+        }
+      })
+      .catch((e: unknown) => {
+        if (!cancelled) {
+          setError(e instanceof ApiClientError ? e.message : 'Impossible de charger les cartes')
+          setCards([])
+        }
+      })
+    return () => {
+      cancelled = true
+    }
+  }, [])
+
+  if (error) {
+    return <p role="alert" className="text-red-600">{error}</p>
+  }
+  if (cards === null) {
+    return <p aria-busy="true">Chargement…</p>
+  }
+  if (cards.length === 0) {
+    return <p role="status">Aucune carte pour le moment.</p>
+  }
+
+  return (
+    <ul className="divide-y divide-slate-200">
+      {cards.map((card) => (
+        <li key={card.id}>
+          <Link
+            href={`/cards/${card.id}`}
+            className="flex items-center justify-between px-4 py-3 hover:bg-slate-50"
+          >
+            <span className="font-medium">{card.question}</span>
+            <span className="rounded-full bg-slate-100 px-2 py-0.5 text-xs text-slate-600">
+              {card.theme}
+            </span>
+          </Link>
+        </li>
+      ))}
+    </ul>
+  )
+}