feat: migrate ESLint to v9 flat config

- Replace .eslintrc.json with eslint.config.mjs
- Simplify configuration using @antfu/eslint-config
- Add necessary ESLint plugin dependencies
- Disable overly strict style rules
- Set package.json type to module for ESM support
- Fix ESLint disable comment format

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/components/sidebar/index.tsx

@@ -16,7 +16,7 @@ function classNames(...classes: any[]) {
 
 const MAX_CONVERSATION_LENTH = 20
 
-export type ISidebarProps = {
+export interface ISidebarProps {
   copyRight: string
   currentId: string
   onCurrentIdChange: (id: string) => void
@@ -38,7 +38,8 @@ const Sidebar: FC<ISidebarProps> = ({
         <div className="flex flex-shrink-0 p-4 !pb-0">
           <Button
             onClick={() => { onCurrentIdChange('-1') }}
-            className="group block w-full flex-shrink-0 !justify-start !h-9 text-primary-600 items-center text-sm">
+            className="group block w-full flex-shrink-0 !justify-start !h-9 text-primary-600 items-center text-sm"
+          >
             <PencilSquareIcon className="mr-2 h-4 w-4" /> {t('app.chat.newChat')}
           </Button>
         </div>