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/image-uploader/image-link-input.tsx

@@ -5,7 +5,7 @@ import Button from '@/app/components/base/button'
 import type { ImageFile } from '@/types/app'
 import { TransferMethod } from '@/types/app'
 
-type ImageLinkInputProps = {
+interface ImageLinkInputProps {
   onUpload: (imageFile: ImageFile) => void
 }
 const regex = /^(https?|ftp):\/\//