Fix eslint no-undef violations (#58233)

Author: heiskr

eslint.config.ts

@@ -25,6 +25,16 @@ export default [
         ...globals.node,
         ...globals.commonjs,
         ...globals.es2020,
+        // Fetch API types for TypeScript
+        RequestInit: 'readonly',
+        RequestInfo: 'readonly',
+        HeadersInit: 'readonly',
+        JSX: 'readonly',
+        // Node.js types for TypeScript
+        BufferEncoding: 'readonly',
+        NodeJS: 'readonly',
+        // cheerio namespace for TypeScript
+        cheerio: 'readonly',
       },
       parserOptions: {
         requireConfigFile: false,
@@ -87,7 +97,6 @@ export default [
       // Disabled rules to review
       'github/no-then': 'off', // 30+
       '@typescript-eslint/ban-ts-comment': 'off', // 50+
-      'no-undef': 'off', // 50+
       'no-shadow': 'off', // 150+
       'prefer-template': 'off', // 150+
       'github/array-foreach': 'off', // 250+

src/app/client-layout.tsx

@@ -1,7 +1,8 @@
 'use client'
 
+import React, { useEffect, useMemo, useState } from 'react'
+import type { JSX } from 'react'
 import { ThemeProvider } from '@primer/react'
-import { useEffect, useMemo, useState } from 'react'
 
 import { LocaleProvider } from '@/app/lib/locale-context'
 import { useDetectLocale } from '@/app/lib/use-detect-locale'

src/app/components/AppRouterLanguagesContext.tsx

@@ -1,6 +1,6 @@
 'use client'
 
-import { createContext, useContext } from 'react'
+import React, { createContext, useContext } from 'react'
 import { languages, type LanguageCode } from '@/languages/lib/languages'
 
 export type AppRouterLanguageItem = {

src/app/layout.tsx

@@ -1,6 +1,7 @@
 import '@/frame/stylesheets/index.scss'
 import type { Metadata, Viewport } from 'next'
 import { ReactNode } from 'react'
+import type { JSX } from 'react'
 
 export const metadata: Metadata = {
   title: {

src/app/lib/locale-context.tsx

@@ -1,6 +1,7 @@
 'use client'
 
 import { createContext, useContext, ReactNode, useMemo } from 'react'
+import type { JSX } from 'react'
 import { languages, languageKeys, type LanguageCode } from '@/languages/lib/languages'
 
 interface LocaleContextType {

src/app/types.ts

@@ -2,6 +2,7 @@
  * Enhanced type definitions for the app router with strict validation
  */
 
+import React from 'react'
 import type { LanguageCode } from '@/languages/lib/languages'
 
 // Core theme types with strict validation

src/automated-pipelines/components/AutomatedPage.tsx

@@ -1,3 +1,4 @@
+import React from 'react'
 import { DefaultLayout } from '@/frame/components/DefaultLayout'
 import { ArticleTitle } from '@/frame/components/article/ArticleTitle'
 import { MarkdownContent } from '@/frame/components/ui/MarkdownContent'

src/automated-pipelines/components/AutomatedPageContext.tsx

@@ -1,4 +1,5 @@
 import { createContext, useContext } from 'react'
+import type { JSX } from 'react'
 import type { MiniTocItem } from '@/frame/components/context/ArticleContext'
 
 export type AutomatedPageContextT = {

src/events/components/Survey.tsx

@@ -1,4 +1,4 @@
-import { useState, useRef, useEffect } from 'react'
+import React, { useState, useRef, useEffect } from 'react'
 import cx from 'classnames'
 import { useRouter } from 'next/router'
 import { ThumbsdownIcon, ThumbsupIcon } from '@primer/octicons-react'

src/frame/components/DefaultLayout.tsx

@@ -1,3 +1,4 @@
+import React from 'react'
 import Head from 'next/head'
 import { useRouter } from 'next/router'