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/tooltip-plus/index.tsx

@@ -2,7 +2,7 @@
 import type { FC } from 'react'
 import React, { useState } from 'react'
 import { PortalToFollowElem, PortalToFollowElemContent, PortalToFollowElemTrigger } from '@/app/components/base/portal-to-follow-elem'
-export type TooltipProps = {
+export interface TooltipProps {
   position?: 'top' | 'right' | 'bottom' | 'left'
   triggerMethod?: 'hover' | 'click'
   popupContent: React.ReactNode
@@ -13,7 +13,7 @@ const arrow = (
   <svg className="absolute text-white h-2 w-full left-0 top-full" x="0px" y="0px" viewBox="0 0 255 255"><polygon className="fill-current" points="0,0 127.5,127.5 255,0"></polygon></svg>
 )
 
-const Tooltip: FC< TooltipProps> = ({
+const Tooltip: FC<TooltipProps> = ({
   position = 'top',
   triggerMethod = 'hover',
   popupContent,