feat: enhance theme management and image caching functionality

src/i18n/index.ts

@@ -1,6 +1,6 @@
 import { createI18n, type I18n, type I18nOptions } from 'vue-i18n';
 import { SUPPORTED_LANGUAGE_CODES, SUPPORTED_LANGUAGES, NAMESPACES, type LanguageCode } from './constants';
-import { resolveSupportedLanguage, detectSystemLanguage } from './resolver';
+import { resolveSupportedLanguage } from './resolver';
 
 // 使用 import.meta.glob 动态加载所有语言文件
 // 文件路径模式：./locales/{语言}/{命名空间}.json
@@ -34,32 +34,12 @@ function buildResources() {
   return resources;
 }
 
-// 获取持久化的语言设置（稍后由 Pinia store 提供）
-function getPersistedLanguage(): LanguageCode | null {
-  try {
-    const saved = localStorage.getItem('zn-language');
-    return saved && SUPPORTED_LANGUAGE_CODES.includes(saved as LanguageCode) ? saved as LanguageCode : null;
-  } catch {
-    return null;
-  }
-}
-
-// 确定初始语言：持久化设置 > 系统语言 > 默认中文
-function determineInitialLocale(): LanguageCode {
-  const persisted = getPersistedLanguage();
-  if (persisted) return persisted;
-
-  const systemLang = detectSystemLanguage();
-  return systemLang;
-}
-
 async function createI18nInstance() {
   const resources = buildResources();
-  const initialLocale = determineInitialLocale();
 
   const options: I18nOptions = {
     legacy: false,
-    locale: initialLocale,
+    locale: 'zh',
     fallbackLocale: 'zh',
     messages: resources, // 使用构建的资源对象
     availableLocales: SUPPORTED_LANGUAGE_CODES,
@@ -85,11 +65,6 @@ export async function setLanguage(lang: LanguageCode, _i18n?: I18n) {
   }
 
   (__i18n.global.locale as unknown as { value: LanguageCode }).value = lang;
-  
-  // 持久化到 localStorage（稍后由 Pinia store 处理）
-  try {
-    localStorage.setItem('zn-language', lang);
-  } catch {}
 }
 
 export function getLanguage() {