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/chat/thought/index.tsx

@@ -5,7 +5,7 @@ import type { ThoughtItem, ToolInfoInThought } from '../type'
 import Tool from './tool'
 import type { Emoji } from '@/types/tools'
 
-export type IThoughtProps = {
+export interface IThoughtProps {
   thought: ThoughtItem
   allToolIcons: Record<string, string | Emoji>
   isFinished: boolean
@@ -29,8 +29,7 @@ const Thought: FC<IThoughtProps> = ({
 }) => {
   const [toolNames, isValueArray]: [string[], boolean] = (() => {
     try {
-      if (Array.isArray(JSON.parse(thought.tool)))
-        return [JSON.parse(thought.tool), true]
+      if (Array.isArray(JSON.parse(thought.tool))) { return [JSON.parse(thought.tool), true] }
     }
     catch (e) {
     }