fix(reports): add scoped error boundary

frontend/app/[locale]/(protected)/reports/error.tsx

@@ -0,0 +1,40 @@
+"use client";
+
+import { useEffect } from "react";
+import { Link } from "@/i18n/navigation";
+
+export default function ReportsError({
+  error,
+  reset,
+}: {
+  error: Error & { digest?: string };
+  reset: () => void;
+}) {
+  useEffect(() => {
+    console.error("Reports route error:", error);
+  }, [error]);
+
+  return (
+    <main className="flex min-h-[60vh] flex-col items-center justify-center gap-4 px-4 text-center">
+      <h1 className="text-3xl font-bold text-gray-900">Reports unavailable</h1>
+      <p className="max-w-md text-sm text-gray-500">
+        Reports could not be loaded. Try again or return to your dashboard while other pages remain available.
+      </p>
+      <div className="flex gap-3">
+        <button
+          type="button"
+          onClick={() => reset()}
+          className="rounded-lg bg-blue-600 px-4 py-2 text-sm font-medium text-white hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500"
+        >
+          Try again
+        </button>
+        <Link
+          href="/"
+          className="rounded-lg border border-gray-300 px-4 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50 focus:outline-none focus:ring-2 focus:ring-gray-400"
+        >
+          Back to dashboard
+        </Link>
+      </div>
+    </main>
+  );
+}

frontend/test-utils/reports-error.test.tsx

@@ -0,0 +1,29 @@
+import React from "react";
+import { fireEvent, render, screen } from "@testing-library/react";
+import ReportsError from "@/app/[locale]/(protected)/reports/error";
+
+const mockReset = jest.fn();
+
+jest.mock("@/i18n/navigation", () => ({
+  Link: ({ children, ...props }: React.AnchorHTMLAttributes<HTMLAnchorElement>) => (
+    <a {...props}>{children}</a>
+  ),
+}));
+
+describe("ReportsError", () => {
+  beforeEach(() => mockReset.mockClear());
+
+  it("renders a reports-scoped error with a retry action", () => {
+    render(<ReportsError error={new Error("reports request failed")} reset={mockReset} />);
+
+    expect(screen.getByRole("heading", { name: "Reports unavailable" })).toBeInTheDocument();
+    fireEvent.click(screen.getByRole("button", { name: "Try again" }));
+    expect(mockReset).toHaveBeenCalledTimes(1);
+  });
+
+  it("provides navigation back to the dashboard", () => {
+    render(<ReportsError error={new Error("reports request failed")} reset={mockReset} />);
+
+    expect(screen.getByRole("link", { name: "Back to dashboard" })).toHaveAttribute("href", "/");
+  });
+});