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/components/Header.tsx

@@ -1,12 +1,12 @@
-import { useLanguage } from '../contexts/LanguageContext';
-import { t } from '../i18n/translations';
+import { useLanguage } from '../contexts/LanguageContext'
+import { t } from '../i18n/translations'
 
 interface HeaderProps {
-  simple?: boolean; // For login/register pages
+  simple?: boolean // For login/register pages
 }
 
 export function Header({ simple = false }: HeaderProps) {
-  const { language, setLanguage } = useLanguage();
+  const { language, setLanguage } = useLanguage()
 
   return (
     <header className="glass sticky top-0 z-50 backdrop-blur-xl">
@@ -28,15 +28,19 @@ export function Header({ simple = false }: HeaderProps) {
               )}
             </div>
           </div>
-          
+
           {/* Right - Language Toggle (always show) */}
-          <div className="flex gap-1 rounded p-1" style={{ background: '#1E2329' }}>
+          <div
+            className="flex gap-1 rounded p-1"
+            style={{ background: '#1E2329' }}
+          >
             <button
               onClick={() => setLanguage('zh')}
               className="px-3 py-1.5 rounded text-xs font-semibold transition-all"
-              style={language === 'zh'
-                ? { background: '#F0B90B', color: '#000' }
-                : { background: 'transparent', color: '#848E9C' }
+              style={
+                language === 'zh'
+                  ? { background: '#F0B90B', color: '#000' }
+                  : { background: 'transparent', color: '#848E9C' }
               }
             >
               中文
@@ -44,9 +48,10 @@ export function Header({ simple = false }: HeaderProps) {
             <button
               onClick={() => setLanguage('en')}
               className="px-3 py-1.5 rounded text-xs font-semibold transition-all"
-              style={language === 'en'
-                ? { background: '#F0B90B', color: '#000' }
-                : { background: 'transparent', color: '#848E9C' }
+              style={
+                language === 'en'
+                  ? { background: '#F0B90B', color: '#000' }
+                  : { background: 'transparent', color: '#848E9C' }
               }
             >
               EN
@@ -55,5 +60,5 @@ export function Header({ simple = false }: HeaderProps) {
         </div>
       </div>
     </header>
-  );
+  )
 }