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/icons/utils.tsx

@@ -1,6 +1,6 @@
 import React from 'react'
 
-export type AbstractNode = {
+export interface AbstractNode {
   name: string
   attributes: {
     [key: string]: string
@@ -8,7 +8,7 @@ export type AbstractNode = {
   children?: AbstractNode[]
 }
 
-export type Attrs = {
+export interface Attrs {
   [key: string]: string
 }