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>

website-monitoring-frontend/docker-compose.yml

@@ -0,0 +1,18 @@
+version: "3.8"
+services:
+  frontend:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    ports:
+      - "3000:3000"
+    env_file:
+      - .env
+
+  scan-worker:
+    build:
+      context: ./scanner-worker
+      dockerfile: Dockerfile
+    ports:
+      - "5001:5001"
+    restart: unless-stopped