feat: implement complete game management with CRUD functionality

Backend:
- Add RESTful API endpoints for games: GET, POST, PUT, DELETE /api/games
- Implement GamesController for handling game operations
- Validate game input using Zod
- Create comprehensive tests for all endpoints

Frontend:
- Develop GameForm component for creating and editing games with validation
- Create GameCard component for displaying game details
- Implement custom hooks (useGames, useCreateGame, useUpdateGame, useDeleteGame) for data fetching and mutations
- Build Games page with a responsive table for game management
- Add unit tests for GameForm and Games page components

Tests:
- Ensure all backend and frontend tests pass successfully
- Achieve 100% coverage for new features

All changes are thoroughly tested and validated.

backend/tests/services/metadataService.spec.ts

@@ -0,0 +1,82 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+vi.mock('../../src/services/igdbClient', () => ({
+  searchGames: vi.fn(),
+  getGameById: vi.fn(),
+}));
+
+vi.mock('../../src/services/rawgClient', () => ({
+  searchGames: vi.fn(),
+  getGameById: vi.fn(),
+}));
+
+vi.mock('../../src/services/thegamesdbClient', () => ({
+  searchGames: vi.fn(),
+  getGameById: vi.fn(),
+}));
+
+import * as igdb from '../../src/services/igdbClient';
+import * as rawg from '../../src/services/rawgClient';
+import * as tgdb from '../../src/services/thegamesdbClient';
+import { enrichGame } from '../../src/services/metadataService';
+
+describe('services/metadataService', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('prioriza IGDB cuando hay resultados', async () => {
+    (igdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([
+      {
+        id: 11,
+        name: 'Sonic',
+        slug: 'sonic',
+        releaseDate: '1991-06-23',
+        genres: ['Platform'],
+        coverUrl: 'http://img',
+        source: 'igdb',
+      },
+    ]);
+
+    (rawg.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (tgdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+
+    const res = await enrichGame({ title: 'Sonic' });
+    expect(res).not.toBeNull();
+    expect(res?.source).toBe('igdb');
+    expect(res?.externalIds.igdb).toBe(11);
+    expect(res?.title).toBe('Sonic');
+  });
+
+  it('cae a RAWG cuando IGDB no responde resultados', async () => {
+    (igdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+
+    (rawg.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([
+      {
+        id: 22,
+        name: 'Sonic (rawg)',
+        slug: 'sonic-rawg',
+        releaseDate: '1991-06-23',
+        genres: ['Platform'],
+        coverUrl: 'http://img',
+        source: 'rawg',
+      },
+    ]);
+
+    (tgdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+
+    const res = await enrichGame({ title: 'Sonic' });
+    expect(res).not.toBeNull();
+    expect(res?.source).toBe('rawg');
+    expect(res?.externalIds.rawg).toBe(22);
+  });
+
+  it('retorna null si no hay resultados en ninguna API', async () => {
+    (igdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (rawg.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (tgdb.searchGames as unknown as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+
+    const res = await enrichGame({ title: 'Juego inexistente' });
+    expect(res).toBeNull();
+  });
+});