feat: add user accounts, authentication, and game history with Prisma 7

- Implement user registration and login with NextAuth v5 (email/password, JWT)
- Add authentication modal in UI with login/register tabs
- Create user profile screen showing game statistics and history
- Integrate Prisma 7 ORM with SQLite database for data persistence
- Store game results (mode, path, clicks, time) in database
- Auto-save completed games only when user is authenticated
- Separate business logic into reusable hooks (useSoloGame, useMultiGame)
- Organize UI into composable screen components (HomeScreen, SoloScreen, ProfileScreen, etc)
- Add session persistence across F5 refresh for solo and multiplayer
- Style auth modal, account button, and profile stats dashboard

app/api/games/route.ts

@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from "next/server";
+import { auth } from "../../../auth";
+import { prisma } from "../../../lib/prisma";
+
+// POST /api/games — sauvegarder une partie
+export async function POST(req: NextRequest) {
+  const session = await auth();
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: "Non connecté" }, { status: 401 });
+  }
+
+  const { mode, startArticle, targetArticle, path, clicks, timeSeconds, won } =
+    await req.json() as {
+      mode: string;
+      startArticle: string;
+      targetArticle: string;
+      path: string[];
+      clicks: number;
+      timeSeconds: number;
+      won: boolean;
+    };
+
+  const game = await prisma.game.create({
+    data: {
+      userId: session.user.id,
+      mode,
+      startArticle,
+      targetArticle,
+      path: JSON.stringify(path),
+      clicks,
+      timeSeconds,
+      won,
+    },
+  });
+
+  return NextResponse.json({ id: game.id });
+}
+
+// GET /api/games — historique de l'utilisateur connecté
+export async function GET() {
+  const session = await auth();
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: "Non connecté" }, { status: 401 });
+  }
+
+  const games = await prisma.game.findMany({
+    where: { userId: session.user.id },
+    orderBy: { playedAt: "desc" },
+    take: 50,
+  });
+
+  return NextResponse.json(
+    games.map((g) => ({
+      ...g,
+      path: JSON.parse(g.path) as string[],
+    }))
+  );
+}