test: ajoute des tests automatisés frontend (Vitest) et mobile (Jest)

- Frontend Next.js : Vitest + Testing Library
  - Button (rendu, clic, état loading)
  - auth-store (setAuth, déconnexion, persistance token)
  - script `npm test`, config jsdom + alias @/
- Mobile Expo : Jest (preset jest-expo)
  - getApiError (erreur Axios, validation, erreur générique, sans réponse)
  - script `npm test`, transformIgnorePatterns adapté
- Cahier de tests : section « Outils de test automatisés » (PHPUnit + Vitest + Jest)
  et entrée 6.4 (PV de recette) au sommaire

Suites vertes : backend 15, frontend 6, mobile 4. tsc/lint/build OK, expo-doctor 18/18.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/__tests__/Button.test.tsx

@@ -0,0 +1,30 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import Button from '@/components/ui/Button';
+
+describe('Button', () => {
+  it('affiche son libellé', () => {
+    render(<Button>Enregistrer</Button>);
+    expect(screen.getByRole('button', { name: 'Enregistrer' })).toBeInTheDocument();
+  });
+
+  it('déclenche onClick au clic', () => {
+    const onClick = vi.fn();
+    render(<Button onClick={onClick}>Valider</Button>);
+    fireEvent.click(screen.getByRole('button', { name: 'Valider' }));
+    expect(onClick).toHaveBeenCalledTimes(1);
+  });
+
+  it('est désactivé pendant le chargement et ne déclenche pas onClick', () => {
+    const onClick = vi.fn();
+    render(
+      <Button loading onClick={onClick}>
+        Envoi
+      </Button>
+    );
+    const btn = screen.getByRole('button');
+    expect(btn).toBeDisabled();
+    fireEvent.click(btn);
+    expect(onClick).not.toHaveBeenCalled();
+  });
+});

frontend/src/__tests__/auth-store.test.ts

@@ -0,0 +1,42 @@
+import { describe, it, expect, beforeEach } from 'vitest';
+import { useAuthStore } from '@/lib/auth-store';
+import type { Utilisateur } from '@/types';
+
+const fakeUser = {
+  id: 1,
+  nom: 'Martin',
+  prenom: 'Claire',
+  email: 'claire@email.fr',
+  role: { id: 2, nom: 'membre' },
+} as unknown as Utilisateur;
+
+describe('auth-store', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    useAuthStore.setState({ user: null, token: null, isAuthenticated: false });
+  });
+
+  it('démarre déconnecté', () => {
+    const state = useAuthStore.getState();
+    expect(state.isAuthenticated).toBe(false);
+    expect(state.token).toBeNull();
+  });
+
+  it('setAuth stocke le token et authentifie l\'utilisateur', () => {
+    useAuthStore.getState().setAuth(fakeUser, 'jwt-123');
+    const state = useAuthStore.getState();
+    expect(state.isAuthenticated).toBe(true);
+    expect(state.token).toBe('jwt-123');
+    expect(state.user?.email).toBe('claire@email.fr');
+    expect(localStorage.getItem('cesizen_token')).toBe('jwt-123');
+  });
+
+  it('setAuth(null) déconnecte et purge le token', () => {
+    useAuthStore.getState().setAuth(fakeUser, 'jwt-123');
+    useAuthStore.getState().setAuth(null, null);
+    const state = useAuthStore.getState();
+    expect(state.isAuthenticated).toBe(false);
+    expect(state.token).toBeNull();
+    expect(localStorage.getItem('cesizen_token')).toBeNull();
+  });
+});