chore: finish frontend ESLint migration #18

Enable every plugin recommended preset and replace Biome with ESLint formatting.

Preserve API contracts and JSX whitespace; verify source, tests, builds and tooling.

packages/ui/src/StateView/StateView.test.tsx

@@ -1,6 +1,7 @@
 import { MantineProvider } from "@mantine/core";
 import { render, screen } from "@testing-library/react";
 import { describe, expect, it } from "vitest";
+
 import { LoadingSkeleton } from "../LoadingSkeleton/LoadingSkeleton";
 import { StateView } from "./StateView";