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/base/app-icon/index.tsx

@@ -2,7 +2,7 @@ import type { FC } from 'react'
 import classNames from 'classnames'
 import style from './style.module.css'
 
-export type AppIconProps = {
+export interface AppIconProps {
   size?: 'xs' | 'tiny' | 'small' | 'medium' | 'large'
   rounded?: boolean
   icon?: string