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/jobs/importRunner.spec.ts

@@ -0,0 +1,119 @@
+import { describe, it, expect } from 'vitest';
+import { ImportRunner } from '../../src/jobs/importRunner';
+
+describe('jobs/importRunner', () => {
+  it('enqueue rechaza después de stop', async () => {
+    const runner = new ImportRunner(1);
+    runner.start();
+    runner.stop();
+
+    await expect(runner.enqueue(() => 'x')).rejects.toThrow();
+  });
+
+  it('rechaza tareas en cola tras stop', async () => {
+    const r = new ImportRunner(1);
+
+    // Primera tarea comienza inmediatamente
+    const t1 = r.enqueue(async () => {
+      await new Promise((res) => setTimeout(res, 50));
+      return 'ok1';
+    });
+
+    // Segunda tarea quedará en cola
+    const t2 = r.enqueue(async () => 'ok2');
+
+    // Parar el runner inmediatamente
+    r.stop();
+
+    await expect(t1).resolves.toBe('ok1');
+    await expect(t2).rejects.toThrow(/ImportRunner stopped/);
+
+    const s = r.getStatus();
+    expect(s.completed).toBeGreaterThanOrEqual(1);
+  });
+
+  it('completed incrementa en rechazo', async () => {
+    const runner = new ImportRunner(1);
+    runner.start();
+
+    const p = runner.enqueue(() => Promise.reject(new Error('boom')));
+
+    await expect(p).rejects.toThrow('boom');
+
+    const status = runner.getStatus();
+    expect(status.completed).toBeGreaterThanOrEqual(1);
+
+    runner.stop();
+  });
+
+  it('enqueue resuelve con el resultado de la tarea', async () => {
+    const runner = new ImportRunner(2);
+    runner.start();
+
+    const result = await runner.enqueue(async () => 'ok');
+    expect(result).toBe('ok');
+
+    const status = runner.getStatus();
+    expect(status.completed).toBe(1);
+    expect(status.running).toBe(0);
+    expect(status.queued).toBe(0);
+    expect(status.concurrency).toBe(2);
+
+    runner.stop();
+  });
+
+  it('respeta la concurrencia configurada', async () => {
+    const concurrency = 2;
+    const runner = new ImportRunner(concurrency);
+    runner.start();
+
+    let active = 0;
+    const observed: number[] = [];
+
+    const makeTask = (delay: number) => async () => {
+      active++;
+      observed.push(active);
+      await new Promise((r) => setTimeout(r, delay));
+      active--;
+      return 'done';
+    };
+
+    const promises = [];
+    for (let i = 0; i < 5; i++) {
+      promises.push(runner.enqueue(makeTask(80)));
+    }
+
+    await Promise.all(promises);
+
+    expect(Math.max(...observed)).toBeLessThanOrEqual(concurrency);
+
+    runner.stop();
+  });
+
+  it('getStatus reporta queued, running, completed y concurrency', async () => {
+    const concurrency = 2;
+    const runner = new ImportRunner(concurrency);
+    runner.start();
+
+    const p1 = runner.enqueue(() => new Promise((r) => setTimeout(() => r('a'), 60)));
+    const p2 = runner.enqueue(() => new Promise((r) => setTimeout(() => r('b'), 60)));
+    const p3 = runner.enqueue(() => new Promise((r) => setTimeout(() => r('c'), 60)));
+
+    // allow the runner to start tasks
+    await new Promise((r) => setImmediate(r));
+
+    const statusNow = runner.getStatus();
+    expect(statusNow.concurrency).toBe(concurrency);
+    expect(statusNow.running).toBeLessThanOrEqual(concurrency);
+    expect(statusNow.queued).toBeGreaterThanOrEqual(0);
+
+    await Promise.all([p1, p2, p3]);
+
+    const statusAfter = runner.getStatus();
+    expect(statusAfter.queued).toBe(0);
+    expect(statusAfter.running).toBe(0);
+    expect(statusAfter.completed).toBe(3);
+
+    runner.stop();
+  });
+});