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/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "mercadodevida-backend",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "description": "MercadoDeVida vNext backend - modular monolith skeleton",
+  "engines": {
+    "node": ">=22"
+  },
+  "scripts": {
+    "build": "tsc -p tsconfig.build.json",
+    "start": "node dist/infrastructure/http/server.js",
+    "lint": "eslint . && prettier --check .",
+    "lint:boundaries": "node scripts/check-module-boundaries.mjs src",
+    "typecheck": "tsc -p tsconfig.json --noEmit",
+    "test": "vitest run"
+  },
+  "dependencies": {
+    "fastify": "^5.2.0"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.17.0",
+    "eslint": "^9.17.0",
+    "eslint-config-prettier": "^10.0.0",
+    "prettier": "^3.4.0",
+    "typescript": "^5.7.0",
+    "typescript-eslint": "^8.18.0",
+    "vitest": "^3.0.0"
+  }
+}