chore: remaining biome lint fixes

Safe fixes from the same pass as the biome baseline commit (import
type, arrow function in an inline script) that were missed when
staging by file.

landing/src/components/ui/feature-card.tsx

@@ -1,4 +1,4 @@
-import { ReactNode } from 'react';
+import type { ReactNode } from 'react';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from './card';
 import { cn } from '@/lib/utils';
 

landing/src/components/ui/section.tsx

@@ -1,5 +1,5 @@
 import { cn } from '@/lib/utils';
-import { ReactNode } from 'react';
+import type { ReactNode } from 'react';
 
 interface SectionProps {
   children: ReactNode;

tauri/index.html

@@ -5,7 +5,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>voicebox</title>
     <script>
-      (function () {
+      (() => {
         try {
           var theme = 'system';
           var raw = localStorage.getItem('voicebox-ui');