feat: 更新登入頁面本地存儲鍵名及日誌輸出，簡化 i18n 配置

src/views/Login.vue

@@ -116,7 +116,7 @@ const refreshTitle = computed(() => t('pages.login.refreshTitle'))
 const forgotPasswordHref = ref('/forgot-password')
 const forgotPasswordTarget = ref<string | undefined>(undefined)
 // 記住帳號的 localStorage key
-const rememberStorageKey = ref('playground.login.remember.username')
+const rememberStorageKey = ref('login.remember.username')
 // 驗證碼 API
 const captchaValue = ref('')
 
@@ -183,12 +183,12 @@ const toolbar = computed(() => ({
 
 // 事件處理
 function handleForgotPassword(e: MouseEvent) {
-  console.log('Playground Forgot Password Click:', e)
+  console.log('Forgot Password Click:', e)
 }
 
 function handleChangeLocale(nextLocale: string) {
   locale.value = nextLocale
-  localStorage.setItem('playground.locale', nextLocale)
+  localStorage.setItem('locale', nextLocale)
 }
 
 async function handleCaptchaRefresh() {