feat: App mobile Expo + API mobile dédiée

memento-mobile/ (Expo + React Native + expo-router):
- Auth: login email/password → Bearer token (expo-secure-store)
- Layout: guard auth → redirect /(auth)/login ou /(tabs)/home
- Tabs: Accueil, Carnets, Recherche, Profil
- Screens: login, home (recent notes + quick actions), notebooks list,
  note viewer (WebView HTML), search (texte), notebook detail, profile
- Design: tokens brand-accent (#A47148), ink, concrete, paper, border
- lib/config.ts: API_URL dev/prod configurable
- lib/api.ts: apiFetch avec Bearer token automatique
- lib/store.ts: Zustand auth store (login/logout/restore)

memento-note/ (API mobile dédiée):
- lib/mobile-auth.ts: createMobileToken / verifyMobileToken (HMAC-SHA256, 90j)
- POST /api/mobile/auth/login: email+password → token + user
- GET /api/mobile/auth/me: valider token, retourner profil
- GET /api/mobile/notebooks: liste carnets avec nb notes
- GET /api/mobile/notes: notes récentes (filtre par carnet optionnel)
- GET /api/mobile/notes/[id]: contenu complet d'une note
- GET /api/mobile/search: recherche fulltext titre+contenu

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

memento-note/app/api/mobile/auth/login/route.ts

@@ -0,0 +1,45 @@
+import { NextRequest, NextResponse } from 'next/server'
+import prisma from '@/lib/prisma'
+import bcrypt from 'bcryptjs'
+import { createMobileToken } from '@/lib/mobile-auth'
+
+export async function POST(req: NextRequest) {
+  try {
+    const { email, password } = await req.json()
+    if (!email || !password) {
+      return NextResponse.json({ error: 'Email et mot de passe requis' }, { status: 400 })
+    }
+
+    const user = await prisma.user.findUnique({
+      where: { email: email.toLowerCase().trim() },
+      select: {
+        id: true, name: true, email: true, password: true,
+        subscription: { select: { tier: true } },
+      },
+    })
+
+    if (!user?.password) {
+      return NextResponse.json({ error: 'Identifiants invalides' }, { status: 401 })
+    }
+
+    const valid = await bcrypt.compare(password, user.password)
+    if (!valid) {
+      return NextResponse.json({ error: 'Identifiants invalides' }, { status: 401 })
+    }
+
+    const token = createMobileToken(user.id)
+    return NextResponse.json({
+      token,
+      user: {
+        id: user.id,
+        name: user.name,
+        email: user.email,
+        tier: user.subscription?.tier ?? 'FREE',
+      },
+    })
+  } catch (e) {
+    console.error('[mobile/auth/login]', e)
+    return NextResponse.json({ error: 'Erreur serveur' }, { status: 500 })
+  }
+}
+

memento-note/app/api/mobile/auth/me/route.ts

@@ -0,0 +1,25 @@
+import { NextRequest, NextResponse } from 'next/server'
+import prisma from '@/lib/prisma'
+import { getMobileUserId } from '@/lib/mobile-auth'
+
+export async function GET(req: NextRequest) {
+  const userId = getMobileUserId(req)
+  if (!userId) return NextResponse.json({ error: 'Non autorisé' }, { status: 401 })
+
+  const user = await prisma.user.findUnique({
+    where: { id: userId },
+    select: {
+      id: true, name: true, email: true,
+      subscription: { select: { tier: true } },
+    },
+  })
+  if (!user) return NextResponse.json({ error: 'Introuvable' }, { status: 404 })
+
+  return NextResponse.json({
+    id: user.id,
+    name: user.name,
+    email: user.email,
+    tier: user.subscription?.tier ?? 'FREE',
+  })
+}
+