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/src/app/dashboard/error.tsx

@@ -0,0 +1,28 @@
+"use client";
+
+import { DashboardLayout } from "@/components/layouts/DashboardLayout";
+import { Button } from "@/components/ui/forms/Button";
+import { AlertCircle } from "lucide-react";
+
+export default function DashboardError({
+  error,
+  reset,
+}: {
+  error: Error;
+  reset: () => void;
+}) {
+  return (
+    <DashboardLayout>
+      <div className="flex flex-col items-center justify-center min-h-[60vh]">
+        <div className="text-red-500 mb-4">
+          <AlertCircle className="h-12 w-12" />
+        </div>
+        <h2 className="text-2xl font-bold text-gray-900 mb-2">
+          Something went wrong!
+        </h2>
+        <p className="text-gray-600 mb-4">{error.message}</p>
+        <Button onClick={() => reset()}>Try again</Button>
+      </div>
+    </DashboardLayout>
+  );
+}