Add comprehensive backend test suite (#339)

* add test suite, mostly covers integration testing, tests are only backend side

* workflow runs the correct script

* workflow runs the correct script

* workflow runs the correct script

* unit tests incoming

* Fix multer silent rejections and error handler info leak

- Revert cb(null, false) to cb(new Error(...)) in auth.ts, collab.ts,
  and files.ts so invalid uploads return an error instead of silently
  dropping the file
- Error handler in app.ts now always returns 500 / "Internal server
  error" instead of forwarding err.message to the client

* Use statusCode consistently for multer errors and error handler

- Error handler in app.ts reads err.statusCode to forward the correct
  HTTP status while keeping the response body generic

server/tests/integration/maps.test.ts

@@ -0,0 +1,135 @@
+/**
+ * Maps integration tests.
+ * Covers MAPS-001 to MAPS-008.
+ *
+ * External API calls (Nominatim, Google Places, Wikipedia) are tested at the
+ * input validation level. Full integration tests would require live external APIs.
+ */
+import { describe, it, expect, vi, beforeAll, beforeEach, afterAll } from 'vitest';
+import request from 'supertest';
+import type { Application } from 'express';
+
+const { testDb, dbMock } = vi.hoisted(() => {
+  const Database = require('better-sqlite3');
+  const db = new Database(':memory:');
+  db.exec('PRAGMA journal_mode = WAL');
+  db.exec('PRAGMA foreign_keys = ON');
+  db.exec('PRAGMA busy_timeout = 5000');
+  const mock = {
+    db,
+    closeDb: () => {},
+    reinitialize: () => {},
+    getPlaceWithTags: (placeId: number) => {
+      const place: any = db.prepare(`SELECT p.*, c.name as category_name, c.color as category_color, c.icon as category_icon FROM places p LEFT JOIN categories c ON p.category_id = c.id WHERE p.id = ?`).get(placeId);
+      if (!place) return null;
+      const tags = db.prepare(`SELECT t.* FROM tags t JOIN place_tags pt ON t.id = pt.tag_id WHERE pt.place_id = ?`).all(placeId);
+      return { ...place, category: place.category_id ? { id: place.category_id, name: place.category_name, color: place.category_color, icon: place.category_icon } : null, tags };
+    },
+    canAccessTrip: (tripId: any, userId: number) =>
+      db.prepare(`SELECT t.id, t.user_id FROM trips t LEFT JOIN trip_members m ON m.trip_id = t.id AND m.user_id = ? WHERE t.id = ? AND (t.user_id = ? OR m.user_id IS NOT NULL)`).get(userId, tripId, userId),
+    isOwner: (tripId: any, userId: number) =>
+      !!db.prepare('SELECT id FROM trips WHERE id = ? AND user_id = ?').get(tripId, userId),
+  };
+  return { testDb: db, dbMock: mock };
+});
+
+vi.mock('../../src/db/database', () => dbMock);
+vi.mock('../../src/config', () => ({
+  JWT_SECRET: 'test-jwt-secret-for-trek-testing-only',
+  ENCRYPTION_KEY: 'a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6a7b8c9d0e1f2a3b4c5d6a7b8c9d0e1f2',
+  updateJwtSecret: () => {},
+}));
+
+import { createApp } from '../../src/app';
+import { createTables } from '../../src/db/schema';
+import { runMigrations } from '../../src/db/migrations';
+import { resetTestDb } from '../helpers/test-db';
+import { createUser } from '../helpers/factories';
+import { authCookie } from '../helpers/auth';
+import { loginAttempts, mfaAttempts } from '../../src/routes/auth';
+
+const app: Application = createApp();
+
+beforeAll(() => {
+  createTables(testDb);
+  runMigrations(testDb);
+});
+
+beforeEach(() => {
+  resetTestDb(testDb);
+  loginAttempts.clear();
+  mfaAttempts.clear();
+});
+
+afterAll(() => {
+  testDb.close();
+});
+
+describe('Maps authentication', () => {
+  it('POST /maps/search without auth returns 401', async () => {
+    const res = await request(app)
+      .post('/api/maps/search')
+      .send({ query: 'Paris' });
+    expect(res.status).toBe(401);
+  });
+
+  it('GET /maps/reverse without auth returns 401', async () => {
+    const res = await request(app)
+      .get('/api/maps/reverse?lat=48.8566&lng=2.3522');
+    expect(res.status).toBe(401);
+  });
+});
+
+describe('Maps validation', () => {
+  it('MAPS-001 — POST /maps/search without query returns 400', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .post('/api/maps/search')
+      .set('Cookie', authCookie(user.id))
+      .send({});
+    expect(res.status).toBe(400);
+  });
+
+  it('MAPS-006 — GET /maps/reverse without lat/lng returns 400', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .get('/api/maps/reverse')
+      .set('Cookie', authCookie(user.id));
+    expect(res.status).toBe(400);
+  });
+
+  it('MAPS-007 — POST /maps/resolve-url without url returns 400', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .post('/api/maps/resolve-url')
+      .set('Cookie', authCookie(user.id))
+      .send({});
+    expect(res.status).toBe(400);
+  });
+});
+
+describe('Maps SSRF protection', () => {
+  it('MAPS-007 — POST /maps/resolve-url with internal IP is blocked', async () => {
+    const { user } = createUser(testDb);
+
+    // SSRF: should be blocked by ssrfGuard
+    const res = await request(app)
+      .post('/api/maps/resolve-url')
+      .set('Cookie', authCookie(user.id))
+      .send({ url: 'http://192.168.1.1/admin' });
+    expect(res.status).toBe(400);
+  });
+
+  it('MAPS-007 — POST /maps/resolve-url with loopback IP is blocked', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .post('/api/maps/resolve-url')
+      .set('Cookie', authCookie(user.id))
+      .send({ url: 'http://127.0.0.1/secret' });
+    expect(res.status).toBe(400);
+  });
+});