feat: 新增多语言文案与组件国际化适配

本次提交完成了大量多语言相关的新增与优化工作：
1. 新增充值、案例、会员资产、订单等页面的中文/英文翻译文案
2. 新增企业微信客服、时间选择、支付弹窗等组件的多语言包
3. 优化工具函数与自定义页面的多语言适配，替换硬编码提示文案
4. 新增会员等级规则、积分商品、退款管理等页面的国际化支持
5. 修复企业微信JS-SDK的错误提示文案硬编码问题

lang/en-us/order/payment.js

@@ -96,6 +96,26 @@ export const lang = {
 		confirm: 'OK'
 	},
 
+	// ====== Promotion Description ======
+	promotion: {
+		title: 'Discounts & Gifts',
+		yuan: ' yuan',
+		piece: ' pcs',
+		points: ' points',
+		manjianFirst: 'Spend {limit}{unit}, save {money} yuan',
+		manjianMore: '; Spend {limit}{unit}, save {money} yuan',
+		couponDiscountFirst: 'get {num} {discount}% off coupon',
+		couponDiscountMore: ', get {num} {discount}% off coupon',
+		couponMoneyFirst: 'get {num} {money} yuan coupon',
+		couponMoneyMore: ', get {num} {money} yuan coupon',
+		mansongFirst: 'Spend {limit}{unit}, {text}',
+		mansongMore: '; Spend {limit}{unit}, {text}',
+		pointGain: 'earn {point} points',
+		pointFirst: 'Spend {limit}{unit}, {pointText}',
+		pointMore: '; Spend {limit}{unit}, {pointText}',
+		freeShipping: 'Free shipping on orders over {limit}{unit}'
+	},
+
 	// ====== Buyer Message Popup ======
 	buyerMessagePopup: {
 		title: 'Buyer Message',