refactor: 国际化文本迁移至全局 locales/messages.js

将组件级 i18n 对象重构为统一由全局 locales/messages.js 管理，确保中英文语言切换时正确显示对应文本。

- 新增 utils/i18n.js 国际化工具函数
- 更新 store/$t.mixin.js 翻译混入逻辑
- 迁移 pkgService、pkgBooking、pkgAccount、pkgExplore、pages 等共 58 个组件的中英文文本至全局消息表

pkgService/submit_request/components/DateRangeSelector.vue

@@ -8,7 +8,7 @@
         </view>
       </picker>
     </view>
-    <view class="date-divider">{{ t('dateDivider') }}</view>
+    <view class="date-divider">{{ $tr('至') }}</view>
     <view class="date-item">
       <view class="date-label">{{ resolvedEndLabel }}</view>
       <picker mode="date" @change="onEndChange">
@@ -23,22 +23,6 @@
 <script>
 export default {
   name: 'DateRangeSelector',
-  i18n: {
-    zh: {
-      startLabel: '预计入住',
-      endLabel: '预计离开',
-      startPlaceholder: '请选择入住日期',
-      endPlaceholder: '请选择离开日期',
-      dateDivider: '至'
-    },
-    en: {
-      startLabel: 'Expected Check-in',
-      endLabel: 'Expected Check-out',
-      startPlaceholder: 'Select check-in date',
-      endPlaceholder: 'Select check-out date',
-      dateDivider: 'to'
-    }
-  },
   props: {
     start: {
       type: String,
@@ -67,22 +51,19 @@ export default {
   },
   computed: {
     resolvedStartLabel() {
-      return this.startLabel || this.t('startLabel')
+      return this.startLabel || this.$tr('预计入住')
     },
     resolvedEndLabel() {
-      return this.endLabel || this.t('endLabel')
+      return this.endLabel || this.$tr('预计离开')
     },
     resolvedStartPlaceholder() {
-      return this.startPlaceholder || this.t('startPlaceholder')
+      return this.startPlaceholder || this.$tr('请选择入住日期')
     },
     resolvedEndPlaceholder() {
-      return this.endPlaceholder || this.t('endPlaceholder')
+      return this.endPlaceholder || this.$tr('请选择离开日期')
     }
   },
   methods: {
-    t(key) {
-      return this.$tm('pkgService.submit_request.components.DateRangeSelector', key)
-    },
     onStartChange(e) {
       this.$emit('update:start', e.detail.value)
     },
@@ -128,7 +109,7 @@ export default {
   font-size: 28rpx;
   color: #1A2B4C;
   font-weight: 600;
-  
+
   &.is-empty {
     color: #CBD5E1;
     font-weight: normal;