feat: add ESLint and Prettier with pre-commit hook

- Install ESLint 9 with TypeScript and React support
- Install Prettier with custom configuration (no semicolons)
- Add husky and lint-staged for pre-commit hooks
- Configure lint-staged to auto-fix and format on commit
- Relax ESLint rules to avoid large-scale code changes
- Format all existing code with Prettier (no semicolons)

Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/contexts/LanguageContext.tsx

@@ -1,37 +1,41 @@
-import { createContext, useContext, useState, ReactNode } from 'react';
-import type { Language } from '../i18n/translations';
+import { createContext, useContext, useState, ReactNode } from 'react'
+import type { Language } from '../i18n/translations'
 
 interface LanguageContextType {
-  language: Language;
-  setLanguage: (lang: Language) => void;
+  language: Language
+  setLanguage: (lang: Language) => void
 }
 
-const LanguageContext = createContext<LanguageContextType | undefined>(undefined);
+const LanguageContext = createContext<LanguageContextType | undefined>(
+  undefined
+)
 
 export function LanguageProvider({ children }: { children: ReactNode }) {
   // Initialize language from localStorage or default to English
   const [language, setLanguage] = useState<Language>(() => {
-    const saved = localStorage.getItem('language');
-    return (saved === 'en' || saved === 'zh') ? saved : 'en';
-  });
+    const saved = localStorage.getItem('language')
+    return saved === 'en' || saved === 'zh' ? saved : 'en'
+  })
 
   // Save language to localStorage whenever it changes
   const handleSetLanguage = (lang: Language) => {
-    setLanguage(lang);
-    localStorage.setItem('language', lang);
-  };
+    setLanguage(lang)
+    localStorage.setItem('language', lang)
+  }
 
   return (
-    <LanguageContext.Provider value={{ language, setLanguage: handleSetLanguage }}>
+    <LanguageContext.Provider
+      value={{ language, setLanguage: handleSetLanguage }}
+    >
       {children}
     </LanguageContext.Provider>
-  );
+  )
 }
 
 export function useLanguage() {
-  const context = useContext(LanguageContext);
+  const context = useContext(LanguageContext)
   if (!context) {
-    throw new Error('useLanguage must be used within LanguageProvider');
+    throw new Error('useLanguage must be used within LanguageProvider')
   }
-  return context;
+  return context
 }