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.

src/features/auth/ui/RegisterForm.tsx

@@ -1,5 +1,7 @@
 import type { FC } from "react";
+
 import { useLocation, useNavigate } from "react-router";
+
 import { useAuth } from "../model/auth-context";
 import { AuthForm } from "./AuthForm/AuthForm";
 
@@ -7,16 +9,16 @@ const RegisterForm: FC = () => {
 	const { register } = useAuth();
 	const navigate = useNavigate();
 	const location = useLocation();
-	const returnTo =
-		(location.state as { returnTo?: string } | null)?.returnTo ?? "/accounts";
+	const returnTo
+		= (location.state as null | { returnTo?: string })?.returnTo ?? "/accounts";
 
 	return (
 		<AuthForm
-			register
 			onSubmit={async (email, password) => {
 				await register(email, password);
 				await navigate(returnTo, { replace: true });
 			}}
+			register
 		/>
 	);
 };