feat: stream hashing y entradas en archivos

- Añade `computeHashesFromStream` para hashing desde streams
- Añade `streamArchiveEntry` e integra en `importDirectory` (path codificado con ::)
- Extiende `scanDirectory` para exponer entradas internas, normaliza rutas POSIX y evita traversal; `ARCHIVE_MAX_ENTRIES` configurable
- Limpia listeners en hashing y mejora robustez/logging
- Añade tests unitarios e integración; actualiza mocks a `Mock` types
- CI: instala `unzip` junto a `p7zip` para soportar tests de integración

backend/tests/services/archiveReader.integration.spec.ts

@@ -0,0 +1,54 @@
+import { test, expect } from 'vitest';
+import { promises as fs } from 'fs';
+import path from 'path';
+import { execSync } from 'child_process';
+import { computeHashesFromStream } from '../../src/services/checksumService';
+import { streamArchiveEntry } from '../../src/services/archiveReader';
+import { createHash } from 'crypto';
+
+function hasBinary(bin: string): boolean {
+  try {
+    execSync(`which ${bin}`, { stdio: 'ignore' });
+    return true;
+  } catch (e) {
+    return false;
+  }
+}
+
+const wantIntegration = process.env.INTEGRATION === '1';
+const canCreate = hasBinary('7z') || hasBinary('zip');
+
+if (!wantIntegration) {
+  test.skip('archiveReader integration tests require INTEGRATION=1', () => {});
+} else if (!canCreate) {
+  test.skip('archiveReader integration tests skipped: no archive creation tool (7z or zip) available', () => {});
+} else {
+  test('reads entry from zip using system tools', async () => {
+    const tmpDir = await fs.mkdtemp(path.join(process.cwd(), 'tmp-arc-'));
+    const inner = path.join(tmpDir, 'game.rom');
+    const content = 'QUASAR-INTEGRATION-TEST';
+    await fs.writeFile(inner, content);
+
+    const archivePath = path.join(tmpDir, 'simple.zip');
+
+    // create zip using available tool
+    if (hasBinary('7z')) {
+      execSync(`7z a -tzip ${JSON.stringify(archivePath)} ${JSON.stringify(inner)}`, {
+        stdio: 'ignore',
+      });
+    } else {
+      execSync(`zip -j ${JSON.stringify(archivePath)} ${JSON.stringify(inner)}`, {
+        stdio: 'ignore',
+      });
+    }
+
+    const stream = await streamArchiveEntry(archivePath, path.basename(inner));
+    expect(stream).not.toBeNull();
+    const hashes = await computeHashesFromStream(stream as any);
+
+    const expectedMd5 = createHash('md5').update(content).digest('hex');
+    expect(hashes.md5).toBe(expectedMd5);
+
+    await fs.rm(tmpDir, { recursive: true, force: true });
+  });
+}