feat(i18n): Update language handling and remove unused imports for improved performance

src/app/api/discover/route.ts

@@ -1,5 +1,5 @@
 import { searchSearxng } from '@/lib/searxng';
-import { getLocale } from 'next-intl/server';
+import { DEFAULT_LOCALE } from '@/i18n/locales';
 
 const websitesForTopic = {
   tech: {
@@ -38,10 +38,6 @@ export const GET = async (req: Request) => {
 
     let data = [];
 
-    // derive base language from current locale (e.g., zh-TW -> zh)
-    const locale = await getLocale();
-    const searxLanguage = 'en';
-
     if (mode === 'normal') {
       const seenUrls = new Set();
 
@@ -53,7 +49,7 @@ export const GET = async (req: Request) => {
                 await searchSearxng(`site:${link} ${query}`, {
                   engines: ['google news', 'bing news'],
                   pageno: 1,
-                  language: searxLanguage,
+                  language: DEFAULT_LOCALE,
                 })
               ).results;
             }),
@@ -75,7 +71,7 @@ export const GET = async (req: Request) => {
           {
             engines: ['google news', 'bing news'],
             pageno: 1,
-            language: searxLanguage,
+            language: DEFAULT_LOCALE,
           },
         )
       ).results;

src/app/library/page.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import DeleteChat from '@/components/DeleteChat';
-import { cn, formatTimeDifference, formatRelativeTime } from '@/lib/utils';
+import { cn, formatRelativeTime } from '@/lib/utils';
 import { BookOpenText, ClockIcon, Delete, ScanEye } from 'lucide-react';
 import Link from 'next/link';
 import { useEffect, useState } from 'react';

src/app/page.tsx

@@ -1,5 +1,5 @@
 import ChatWindow from '@/components/ChatWindow';
-import type { Metadata } from 'next';
+import { Metadata } from 'next';
 import { Suspense } from 'react';
 import { getTranslations } from 'next-intl/server';
 

src/app/settings/page.tsx

@@ -9,7 +9,7 @@ import LocaleSwitcher from '@/components/LocaleSwitcher';
 import { ImagesIcon, VideoIcon } from 'lucide-react';
 import Link from 'next/link';
 import { PROVIDER_METADATA } from '@/lib/providers';
-import { useLocale, useTranslations } from 'next-intl';
+import { useTranslations } from 'next-intl';
 
 interface SettingsType {
   chatModelProviders: {
@@ -131,7 +131,6 @@ const SettingsSection = ({
 
 const Page = () => {
   const t = useTranslations('pages.settings');
-  const locale = useLocale();
   const [config, setConfig] = useState<SettingsType | null>(null);
   const [chatModels, setChatModels] = useState<Record<string, any>>({});
   const [embeddingModels, setEmbeddingModels] = useState<Record<string, any>>(

src/components/DeleteChat.tsx

@@ -39,7 +39,7 @@ const DeleteChat = ({
       });
 
       if (res.status != 200) {
-        throw new Error(t('common.errors.failedToDeleteChat'));
+        throw new Error('Failed to delete chat');
       }
 
       const newChats = chats.filter((chat) => chat.id !== chatId);
@@ -50,7 +50,8 @@ const DeleteChat = ({
         window.location.href = '/';
       }
     } catch (err: any) {
-      toast.error(err.message || t('common.errors.failedToDeleteChat'));
+      console.error(err);
+      toast.error(t('common.errors.failedToDeleteChat'));
     } finally {
       setConfirmationDialogOpen(false);
       setLoading(false);

src/components/LocaleBootstrap.tsx

@@ -9,10 +9,8 @@ export default function LocaleBootstrap({
   initialLocale: AppLocale;
 }) {
   useEffect(() => {
-    // 若已有 cookie，跳過
     const hasCookie = /(?:^|; )locale=/.test(document.cookie);
     if (hasCookie) return;
-    // 僅接受支援清單內的語系
     const supported = new Set<string>(LOCALES as readonly string[]);
     const loc = (initialLocale || DEFAULT_LOCALE) as string;
     const chosen = Array.from(supported).find(

src/components/MessageBox.tsx

@@ -218,9 +218,9 @@ const MessageBox = ({
                       className="p-2 text-black/70 dark:text-white/70 rounded-xl hover:bg-light-secondary dark:hover:bg-dark-secondary transition duration-200 hover:text-black dark:hover:text-white"
                     >
                       {speechStatus === 'started' ? (
-                        <StopCircle size={18} aria-label="Stop TTS" />
+                        <StopCircle size={18} />
                       ) : (
-                        <Volume2 size={18} aria-label="Start TTS" />
+                        <Volume2 size={18} />
                       )}
                     </button>
                   </div>

src/components/Navbar.tsx

@@ -1,11 +1,7 @@
 import { Clock, Edit, Share, Trash, FileText, FileDown } from 'lucide-react';
 import { Message } from './ChatWindow';
 import { useEffect, useState, Fragment } from 'react';
-import {
-  formatTimeDifference,
-  formatRelativeTime,
-  formatDate,
-} from '@/lib/utils';
+import { formatRelativeTime, formatDate } from '@/lib/utils';
 import { useLocale, useTranslations } from 'next-intl';
 import DeleteChat from './DeleteChat';
 import {
@@ -168,12 +164,9 @@ const Navbar = ({
           ? `${messages[0].content.substring(0, 20).trim()}...`
           : messages[0].content;
       setTitle(newTitle);
-      // title already set above
     }
   }, [messages]);
 
-  // Removed per-locale relative time uses render-time computation
-
   return (
     <div className="fixed z-40 top-0 left-0 right-0 px-4 lg:pl-[104px] lg:pr-6 lg:px-8 flex flex-row items-center justify-between w-full py-4 text-sm text-black dark:text-white/70 border-b bg-light-primary dark:bg-dark-primary border-light-100 dark:border-dark-200">
       <a

src/i18n/locales.ts

@@ -31,7 +31,7 @@ export const LOCALE_LABELS: Record<AppLocale, string> = {
   de: 'Deutsch',
 };
 
-// Human-readable language name for prompt prefix
+// Human-readable language name for prompt
 export function getPromptLanguageName(loc: string): string {
   const l = (loc || '').toLowerCase();
   const match = (

src/lib/utils.ts

@@ -19,29 +19,6 @@ export const formatDate = (
   return new Intl.DateTimeFormat(locale || undefined, options).format(d);
 };
 
-export const formatTimeDifference = (
-  date1: Date | string,
-  date2: Date | string,
-): string => {
-  date1 = new Date(date1);
-  date2 = new Date(date2);
-
-  const diffInSeconds = Math.floor(
-    Math.abs(date2.getTime() - date1.getTime()) / 1000,
-  );
-
-  if (diffInSeconds < 60)
-    return `${diffInSeconds} second${diffInSeconds !== 1 ? 's' : ''}`;
-  else if (diffInSeconds < 3600)
-    return `${Math.floor(diffInSeconds / 60)} minute${Math.floor(diffInSeconds / 60) !== 1 ? 's' : ''}`;
-  else if (diffInSeconds < 86400)
-    return `${Math.floor(diffInSeconds / 3600)} hour${Math.floor(diffInSeconds / 3600) !== 1 ? 's' : ''}`;
-  else if (diffInSeconds < 31536000)
-    return `${Math.floor(diffInSeconds / 86400)} day${Math.floor(diffInSeconds / 86400) !== 1 ? 's' : ''}`;
-  else
-    return `${Math.floor(diffInSeconds / 31536000)} year${Math.floor(diffInSeconds / 31536000) !== 1 ? 's' : ''}`;
-};
-
 // Locale-aware relative time using Intl.RelativeTimeFormat
 export const formatRelativeTime = (
   date1: Date | string,