feat(18-01): Task 1 — Linux-Paket bis zum Download aus der API (Durchstich)

Die duenne Strecke Skript -> Abbild -> API beweisen (D-08, D-10):

- desktop-collect.sh sammelt AppImage/exe ein, schreibt manifest.json
  (Version, Kanal, Commit, Groesse, SHA-256) ohne Secrets
- apps/api/src/desktop/: neues Modul mit GET /desktop/latest und
  GET /desktop/download/:platform, beide @Public(); Plattform-Whitelist
  vor jedem Dateisystemzugriff, Dateiname ausschliesslich aus dem
  Manifest (T-18-01, T-18-02)
- packages/shared: DesktopPlatform/-Manifest(File)/-Latest(Response)
  Typen
- Dockerfile kopiert desktop-dist/ in die runner-Stufe; desktop-dist/
  per .gitkeep + .gitignore versioniert (leeres Verzeichnis, Pakete
  bleiben ungetrackt)
- HTTP-Durchstich-Spec (8 Tests) via NestFactory, kein fs-Mock; echtes
  Temp-Verzeichnis + unabhaengig berechneter SHA-256

Abweichung: DesktopController braucht @Inject(DesktopService) explizit
— Vitest transpiliert ueber esbuild, das emitDecoratorMetadata nicht
abbildet, sonst bleibt desktopService bei einem echten NestFactory-Bau
undefined (Rule 3, Blocker).

Lokal bewiesen: neu gebautes API-Abbild liefert /desktop/latest (200)
und /desktop/download/linux (200, attachment) aus, auch ueber
/api-proxy/ des Web-Containers.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/api/src/desktop/desktop.service.spec.ts

@@ -0,0 +1,168 @@
+import 'reflect-metadata';
+import * as crypto from 'crypto';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { NestFactory } from '@nestjs/core';
+import { BadRequestException, NotFoundException } from '@nestjs/common';
+import { afterAll, afterEach, beforeAll, describe, expect, it } from 'vitest';
+import { IS_PUBLIC_KEY } from '../auth/decorators/public.decorator';
+import { DesktopController } from './desktop.controller';
+import { DesktopModule } from './desktop.module';
+import { DesktopService } from './desktop.service';
+
+/**
+ * DesktopService/DesktopController.spec — HTTP-Durchstich ueber
+ * NestFactory (Phase 18, Task 1). Kein `fs`-Mock: ein echtes
+ * Temp-Verzeichnis mit einer kleinen Zufallsdatei und einem von Hand
+ * geschriebenen manifest.json, dessen sha256 unabhaengig ueber
+ * crypto.createHash berechnet wird -- der Pruefling erzeugt den
+ * Erwartungswert nicht selbst.
+ *
+ * `DesktopService.getManifest()` liest manifest.json bei JEDEM Aufruf neu
+ * (kein Cache) -- writeManifest() darf die Datei deshalb zwischen Tests
+ * ueberschreiben, ohne den laufenden HTTP-Server neu zu starten.
+ */
+
+const ORIGINAL_ENV = process.env.DESKTOP_DIST_DIR;
+
+let tempDir: string;
+let app: Awaited<ReturnType<typeof NestFactory.create>>;
+let baseUrl: string;
+
+const PACKAGE_NAME = 'test-package.bin';
+let packageSize: number;
+let packageSha256: string;
+
+function writeManifest(files: Record<string, { name: string; size: number; sha256: string }>) {
+  fs.writeFileSync(
+    path.join(tempDir, 'manifest.json'),
+    JSON.stringify({
+      version: '1.1.0',
+      channel: 'dev',
+      commit: 'abc1234',
+      buildTime: '2026-09-16T00:00:00Z',
+      files,
+    }),
+  );
+}
+
+beforeAll(async () => {
+  tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'tessera-desktop-'));
+  const packageBytes = crypto.randomBytes(64 * 1024);
+  fs.writeFileSync(path.join(tempDir, PACKAGE_NAME), packageBytes);
+  packageSize = packageBytes.length;
+  packageSha256 = crypto.createHash('sha256').update(packageBytes).digest('hex');
+
+  writeManifest({ linux: { name: PACKAGE_NAME, size: packageSize, sha256: packageSha256 } });
+
+  process.env.DESKTOP_DIST_DIR = tempDir;
+  app = await NestFactory.create(DesktopModule, { logger: false });
+  await app.listen(0);
+  const address = app.getHttpServer().address();
+  const port = typeof address === 'object' && address ? address.port : 0;
+  baseUrl = `http://127.0.0.1:${port}`;
+});
+
+afterAll(async () => {
+  await app.close();
+  fs.rmSync(tempDir, { recursive: true, force: true });
+  if (ORIGINAL_ENV === undefined) {
+    delete process.env.DESKTOP_DIST_DIR;
+  } else {
+    process.env.DESKTOP_DIST_DIR = ORIGINAL_ENV;
+  }
+});
+
+afterEach(() => {
+  // Default-Manifest fuer den naechsten Test wiederherstellen (Tests 6/7
+  // ueberschreiben es bewusst mit einer anderen Form).
+  writeManifest({ linux: { name: PACKAGE_NAME, size: packageSize, sha256: packageSha256 } });
+});
+
+describe('DesktopService/DesktopController — HTTP-Durchstich (Phase 18)', () => {
+  it('Test 1 (latest, Manifest vorhanden): 200 mit Kopf-Feldern und relativer Download-URL', async () => {
+    const res = await fetch(`${baseUrl}/desktop/latest`);
+    expect(res.status).toBe(200);
+    const body = await res.json();
+    expect(body).toEqual({
+      version: '1.1.0',
+      channel: 'dev',
+      commit: 'abc1234',
+      buildTime: '2026-09-16T00:00:00Z',
+      files: {
+        linux: {
+          name: PACKAGE_NAME,
+          size: packageSize,
+          sha256: packageSha256,
+          url: '/desktop/download/linux',
+        },
+      },
+    });
+  });
+
+  it('Test 2 (getLatest ohne Manifest): eigene Instanz mit leerem Temp-Verzeichnis wirft NotFoundException', () => {
+    const emptyDir = fs.mkdtempSync(path.join(os.tmpdir(), 'tessera-desktop-empty-'));
+    const previous = process.env.DESKTOP_DIST_DIR;
+    process.env.DESKTOP_DIST_DIR = emptyDir;
+    try {
+      const service = new DesktopService();
+      expect(() => service.getLatest()).toThrow(NotFoundException);
+    } finally {
+      process.env.DESKTOP_DIST_DIR = previous;
+      fs.rmSync(emptyDir, { recursive: true, force: true });
+    }
+  });
+
+  it('Test 3 (download/linux): 200, attachment-Header und Body-Hash stimmen mit dem Manifest ueberein', async () => {
+    const res = await fetch(`${baseUrl}/desktop/download/linux`);
+    expect(res.status).toBe(200);
+    expect(res.headers.get('content-disposition')).toBe(`attachment; filename="${PACKAGE_NAME}"`);
+    expect(res.headers.get('content-type')).toBe('application/octet-stream');
+    expect(res.headers.get('content-length')).toBe(String(packageSize));
+    const buffer = Buffer.from(await res.arrayBuffer());
+    const hash = crypto.createHash('sha256').update(buffer).digest('hex');
+    expect(hash).toBe(packageSha256);
+  });
+
+  it('Test 4 (Plattform-Whitelist + Traversal ueber HTTP): mac und ..%2F..%2Fetc%2Fpasswd enden mit 400', async () => {
+    const resMac = await fetch(`${baseUrl}/desktop/download/mac`);
+    expect(resMac.status).toBe(400);
+
+    const resTraversal = await fetch(`${baseUrl}/desktop/download/..%2F..%2Fetc%2Fpasswd`);
+    expect(resTraversal.status).toBe(400);
+  });
+
+  it('Test 5 (Whitelist vor Dateisystem): nicht existierendes Verzeichnis + mac wirft BadRequestException, nicht NotFoundException', () => {
+    const missingDir = path.join(os.tmpdir(), 'tessera-desktop-does-not-exist-' + Date.now());
+    const previous = process.env.DESKTOP_DIST_DIR;
+    process.env.DESKTOP_DIST_DIR = missingDir;
+    try {
+      const service = new DesktopService();
+      expect(() => service.getPackage('mac')).toThrow(BadRequestException);
+    } finally {
+      process.env.DESKTOP_DIST_DIR = previous;
+    }
+  });
+
+  it('Test 6 (Manifest nur mit windows): download/linux endet mit 404', async () => {
+    writeManifest({
+      windows: { name: 'Tessera-Setup-1.1.0.exe', size: 123, sha256: 'a'.repeat(64) },
+    });
+    const res = await fetch(`${baseUrl}/desktop/download/linux`);
+    expect(res.status).toBe(404);
+  });
+
+  it('Test 7 (manipulierter Name im Manifest): "../x.AppImage" endet mit 404', async () => {
+    writeManifest({
+      linux: { name: '../x.AppImage', size: 123, sha256: 'a'.repeat(64) },
+    });
+    const res = await fetch(`${baseUrl}/desktop/download/linux`);
+    expect(res.status).toBe(404);
+  });
+
+  it('Test 8 (bewusst oeffentlich): getLatest und download tragen @Public()', () => {
+    expect(Reflect.getMetadata(IS_PUBLIC_KEY, DesktopController.prototype.getLatest)).toBe(true);
+    expect(Reflect.getMetadata(IS_PUBLIC_KEY, DesktopController.prototype.download)).toBe(true);
+  });
+});