refactor: establish local frontend workspace boundaries

OpenSpec change: evolve-frontend-stack

packages/ui/src/StateView.test.tsx

@@ -0,0 +1,37 @@
+import { MantineProvider } from "@mantine/core";
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+import { LoadingSkeleton } from "./LoadingSkeleton";
+import { StateView } from "./StateView";
+
+describe("StateView", () => {
+	it("renders an accessible structural loading region", () => {
+		render(
+			<MantineProvider>
+				<LoadingSkeleton label="Загрузка">
+					<div />
+				</LoadingSkeleton>
+			</MantineProvider>,
+		);
+
+		expect(screen.getByRole("status", { name: "Загрузка" })).toHaveAttribute(
+			"aria-busy",
+			"true",
+		);
+	});
+
+	it("renders an accessible error state", () => {
+		render(
+			<MantineProvider>
+				<StateView
+					error
+					text="Попробуйте обновить страницу позже."
+					title="Что-то пошло не так"
+				/>
+				,
+			</MantineProvider>,
+		);
+
+		expect(screen.getByRole("alert")).toHaveTextContent("Что-то пошло не так");
+	});
+});