feat: ATM10-Statistikportal

Statistikportal für den All-the-Mods-10-Server (Minecraft 1.21.1, NeoForge 21.1):

- mod/: serverseitige NeoForge-Mod atmstats – Ereignisse, Live-Zähler, Servergesundheit,
  FTB-Dateien; Outbox auf der Festplatte, signierter gzip-Versand per HTTPS mit Backoff
- backend/: Fastify + PostgreSQL – idempotenter Ingest, Projektionen, Parser für SNBT,
  FTB Quests/Teams, world/stats, world/advancements und latest.log; Ranglisten, Snapshots,
  Retention, öffentliche API, SSE-Live-Updates, Admin mit argon2/CSRF, SFTP-Worker
- web/: Next.js-Dashboard – Übersicht, Ranglisten, Spielerprofile, ATM10, Server,
  Datenquellen, Verwaltung
- shared/: Protokoll v1 und API-Typen; tools/: Simulator, Log-Anonymisierer, RCON-Client
- deploy/: Docker Compose hinter Traefik, Backup; docs/: Architektur, Datenquellen, Betrieb

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/test/scheduler.test.ts

@@ -0,0 +1,36 @@
+import type { Pool } from 'pg';
+import { afterAll, beforeEach, describe, expect, it } from 'vitest';
+import { runJob } from '../src/worker/scheduler.ts';
+import { closeTestPool, getTestPool, resetDb } from './helpers/db.ts';
+
+let pool: Pool;
+beforeEach(async () => {
+  pool = await getTestPool();
+  await resetDb(pool);
+});
+afterAll(closeTestPool);
+
+describe('runJob', () => {
+  it('never runs the same job twice concurrently', async () => {
+    let running = 0;
+    let maxRunning = 0;
+    const job = async () => {
+      running++;
+      maxRunning = Math.max(maxRunning, running);
+      await new Promise((r) => setTimeout(r, 200));
+      running--;
+    };
+    const results = await Promise.all([runJob(pool, 'x', 900_001, job), runJob(pool, 'x', 900_001, job)]);
+    expect(maxRunning).toBe(1);
+    expect(results.sort()).toEqual(['locked', 'ok']);
+  });
+
+  it('records failures in app_errors', async () => {
+    const r = await runJob(pool, 'sftp', 900_002, async () => {
+      throw new Error('connection refused');
+    });
+    expect(r).toBe('error');
+    const { rows } = await pool.query('SELECT source, message FROM app_errors');
+    expect(rows).toEqual([{ source: 'sftp', message: 'connection refused' }]);
+  });
+});