feat: 新增多语言配置并优化语言加载逻辑

1. 新增多个页面的中英文多语言词条，包括会员卡协议、积分商品、收银台等
2. 新增退款商品选择、微信支付、电子名片等页面的语言包
3. 优化lang.js语言加载逻辑，支持蛇形命名转换和多路径匹配，完善$lang调用兼容处理

lang/en-us/contact/contact.js

@@ -1,11 +1,27 @@
 export const lang = {
+	title: 'Business Card',
 
 	// Section titles
 	enterpriseFiles: 'Enterprise Files',
 	enterpriseVideos: 'Enterprise Videos',
+	onlineMessage: 'Online Message',
+	exclusiveCustomerService: 'Exclusive Customer Service',
 
 	// Share
 	contactUs: 'Contact Us',
+	share: 'Share',
+	call: 'Call',
+	copy: 'Copy',
+	oneClickNavigation: 'Navigation',
+
+	// Message form
+	name: 'Name',
+	pleaseEnterName: 'Please enter your name',
+	contactInfo: 'Contact Info',
+	pleaseEnterMobile: 'Please enter your mobile number',
+	messageContent: 'Message',
+	pleaseEnterMessage: 'Please enter your message',
+	submit: 'Submit',
 
 	// Toast messages
 	videoUrlNotExist: 'Video URL does not exist',
@@ -14,5 +30,7 @@ export const lang = {
 	pleaseFillMessage: 'Please fill in the message content',
 	submitSuccess: 'Submitted successfully',
 	submitFailed: 'Submission failed, please try again',
+	copySuccess: 'Copied successfully',
+	copyFailed: 'Copy failed',
 
 }