feat: import job runner in-memory

- Añade ImportRunner en memoria con concurrencia configurable
- Tests TDD para enqueue, concurrencia y comportamiento tras stop
- Actualiza /api/import/scan para encolar jobs y registrar errores
- Ajusta tsconfig.json para incluir tests en comprobaciones de tipo

backend/tests/services/datVerifier.spec.ts

@@ -0,0 +1,35 @@
+import { describe, it, expect } from 'vitest';
+import path from 'path';
+import fs from 'fs';
+import { parseDat, verifyRomAgainstDat } from '../../src/services/datVerifier';
+
+const fixturesDir = path.join(__dirname, '..', 'fixtures');
+const datPath = path.join(fixturesDir, 'dats', 'sample-no-intro.dat.xml');
+const simpleRom = path.join(fixturesDir, 'simple-rom.bin');
+
+const runIntegration = !!process.env.INTEGRATION;
+const describeIf = runIntegration ? describe : describe.skip;
+
+describeIf('services/datVerifier', () => {
+  it('parsea DAT xml', () => {
+    const xml = fs.readFileSync(datPath, 'utf8');
+    const parsed = parseDat(xml);
+    expect(parsed).toBeDefined();
+  });
+
+  it('verifica rom contra DAT', async () => {
+    const stats = fs.statSync(simpleRom);
+    const romMeta = {
+      filename: 'simple-rom.bin',
+      size: stats.size,
+      md5: 'placeholder',
+      sha1: 'placeholder',
+      crc32: 'placeholder',
+    } as any;
+
+    const xml = fs.readFileSync(datPath, 'utf8');
+    const parsed = parseDat(xml);
+    const res = await verifyRomAgainstDat(romMeta, parsed);
+    expect(res).toBeDefined();
+  });
+});