feat: initialize monorepo with full dev team best practices

- Unified monorepo with backend (Express), frontend (Next.js), and devops
- Backend: ESLint, Prettier, Jest tests (3 passing), health endpoint, .env.example
- Frontend: Fixed build errors, fixed all lint errors (0 remaining), tests passing
- DevOps: Docker Compose with PostgreSQL, backend, frontend + healthchecks
- CI/CD: 3 GitHub Actions workflows (backend, frontend, docker integration)
- DX: Husky pre-commit hooks with smart change detection
- Docs: Root README with architecture, CONTRIBUTING.md, PR template

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

package.json

@@ -0,0 +1,30 @@
+{
+  "name": "website-monitoring",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Full-stack website monitoring platform with Lighthouse performance auditing",
+  "scripts": {
+    "dev:backend": "cd website-monitoring-backend && npm run dev",
+    "dev:frontend": "cd website-monitoring-frontend && npm run dev",
+    "dev": "concurrently \"npm run dev:backend\" \"npm run dev:frontend\"",
+    "build:backend": "cd website-monitoring-backend && npm run build",
+    "build:frontend": "cd website-monitoring-frontend && npm run build",
+    "build": "npm run build:backend && npm run build:frontend",
+    "test:backend": "cd website-monitoring-backend && npm test",
+    "test:frontend": "cd website-monitoring-frontend && npm test",
+    "test": "npm run test:backend && npm run test:frontend",
+    "lint:backend": "cd website-monitoring-backend && npm run lint",
+    "lint:frontend": "cd website-monitoring-frontend && npm run lint",
+    "lint": "npm run lint:backend && npm run lint:frontend",
+    "docker:up": "docker compose -f website-monitoring-devops/docker-compose.yml up --build",
+    "docker:down": "docker compose -f website-monitoring-devops/docker-compose.yml down",
+    "prepare": "husky"
+  },
+  "devDependencies": {
+    "concurrently": "^9.1.0",
+    "husky": "^9.1.0"
+  },
+  "engines": {
+    "node": ">=18.0.0"
+  }
+}