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>

.husky/pre-commit

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+# Check if backend files changed
+if git diff --cached --name-only | grep -q "^website-monitoring-backend/"; then
+  echo "🔍 Linting backend..."
+  cd website-monitoring-backend && npx eslint src/ || exit 1
+  cd ..
+fi
+
+# Check if frontend files changed
+if git diff --cached --name-only | grep -q "^website-monitoring-frontend/"; then
+  echo "🔍 Linting frontend..."
+  cd website-monitoring-frontend && npx next lint || exit 1
+  cd ..
+fi
+
+echo "✅ Pre-commit checks passed"