feat(i18n): add multi-language support (en/zh) across app and server

Implement useLocale composable and shared translation dictionaries
Translate public pages, booking flow, and receipt views
Store booking locale to send localized WhatsApp notifications

server/utils/bookings.ts

@@ -4,6 +4,7 @@ import {
   formatBookingCurrency
 } from '~~/shared/booking'
 import { hasValidFullName, isValidPhoneNumber, normalizeFullName, normalizePhoneNumber } from '~~/shared/auth'
+import { resolveLocale } from '~~/shared/i18n'
 
 import { assertBadRequest } from './http'
 
@@ -14,6 +15,7 @@ export function parseCreateBookingInput(body: {
   quantity?: number
   ticketType?: TicketType
   personInChargeId?: string
+  locale?: string | null
 }) {
   const customerName = normalizeFullName(body.customerName || '')
   const customerPhone = normalizePhoneNumber(body.customerPhone || '')
@@ -21,6 +23,7 @@ export function parseCreateBookingInput(body: {
   const ticketType = typeof body.ticketType === 'string' ? body.ticketType.trim().toLowerCase() : body.ticketType
   const quantity = Number(body.quantity)
   const personInChargeId = (body.personInChargeId || '').trim()
+  const locale = resolveLocale(body.locale)
 
   assertBadRequest(hasValidFullName(customerName), 'Guest or organizer name must be at least 2 characters')
   assertBadRequest(isValidPhoneNumber(customerPhone), 'Phone number must include a country code, e.g. +60123456789')
@@ -35,7 +38,8 @@ export function parseCreateBookingInput(body: {
     bookingMode,
     quantity,
     ticketType,
-    personInChargeId
+    personInChargeId,
+    locale
   }
 }
 
@@ -66,6 +70,21 @@ export function parseBookingPicTransferInput(body: {
 }
 
 export function buildBookingMessage(booking: PublicBooking, confirmationUrl: string) {
+  if (booking.locale === 'zh') {
+    return [
+      `我想预订 ${booking.event.title} 的票券。`,
+      '',
+      `姓名：${booking.customerName}`,
+      `联络号码：${booking.customerPhone}`,
+      `座位：${booking.seatCount}`,
+      `票券类别：${booking.ticketLabel || booking.ticketType.toUpperCase()}`,
+      `总价：${formatBookingCurrency(booking.totalPrice, booking.locale)}`,
+      '',
+      '负责人确认链接：',
+      confirmationUrl
+    ].join('\n')
+  }
+
   return [
     `I'd like to book tickets for the ${booking.event.title}.`,
     '',
@@ -73,7 +92,7 @@ export function buildBookingMessage(booking: PublicBooking, confirmationUrl: str
     `Phone Number: ${booking.customerPhone}`,
     `Seats: ${booking.seatCount}`,
     `Ticket Category: ${booking.ticketLabel || booking.ticketType.toUpperCase()}`,
-    `Total Price: ${formatBookingCurrency(booking.totalPrice)}`,
+    `Total Price: ${formatBookingCurrency(booking.totalPrice, booking.locale)}`,
     '',
     'PIC confirmation link:',
     confirmationUrl