feat(F-001): scaffold modular monolith skeleton with boundary checker

- TypeScript + Fastify skeleton under project/ (src/modules, shared, infrastructure, app)
- scripts/check-module-boundaries.mjs enforcing module public-API rules (tested with fixtures)
- GET /health endpoint, error envelope without stack leakage
- specs/F-001-scaffold (SPEC/DESIGN/TASKS/TESTS), spec/tech.md dependency justification
- 30-ticket MercadoDeVida roadmap in backlog/features.json, spec/roadmap.md
- All gates approved: reviewer, security, qa; verify.sh green

project/src/modules/health/api/health.routes.ts

@@ -0,0 +1,11 @@
+import type { FastifyInstance } from 'fastify';
+
+interface HealthResponse {
+  status: 'ok';
+}
+
+export async function registerHealthRoutes(app: FastifyInstance): Promise<void> {
+  app.get('/health', async (): Promise<HealthResponse> => {
+    return { status: 'ok' };
+  });
+}

project/src/modules/health/index.ts

@@ -0,0 +1,5 @@
+/**
+ * Public API of the health module. Everything a module exposes to the
+ * outside world goes through this file.
+ */
+export { registerHealthRoutes } from './api/health.routes.js';

project/src/modules/health/tests/health.test.ts

@@ -0,0 +1,18 @@
+import Fastify from 'fastify';
+import { describe, expect, it } from 'vitest';
+import { registerHealthRoutes } from '../index.js';
+
+describe('health module API', () => {
+  it('GET /health returns 200 and status ok', async () => {
+    const app = Fastify({ logger: false });
+    await app.register(async (instance) => {
+      await registerHealthRoutes(instance);
+    });
+
+    const response = await app.inject({ method: 'GET', url: '/health' });
+
+    expect(response.statusCode).toBe(200);
+    expect(response.json()).toEqual({ status: 'ok' });
+    await app.close();
+  });
+});