feat(i18n): 管理端与玩家端三语支持（中/英/马来语）

- 管理后台 adminT 文案库、结算与代理端页面、表单校验
- 玩家端 vue-i18n 补全首页/公告/串关与 ms 文案
- Element Plus ms 语言包与共享 locale 工具

apps/api/src/domains/operations/content/content.service.ts

@@ -1,6 +1,18 @@
 import { Injectable } from '@nestjs/common';
 import { PrismaService } from '../../../shared/prisma/prisma.service';
 
+function pickContentTranslation<T extends { locale: string }>(
+  translations: T[],
+  locale: string,
+): T | undefined {
+  const chain = [locale, 'en-US', 'zh-CN'];
+  for (const loc of chain) {
+    const hit = translations.find((tr) => tr.locale === loc);
+    if (hit) return hit;
+  }
+  return translations[0];
+}
+
 @Injectable()
 export class ContentService {
   constructor(private prisma: PrismaService) {}
@@ -19,10 +31,7 @@ export class ContentService {
     });
 
     return items.map((item) => {
-      const t =
-        item.translations.find((tr) => tr.locale === locale) ||
-        item.translations.find((tr) => tr.locale === 'en-US') ||
-        item.translations[0];
+      const t = pickContentTranslation(item.translations, locale);
       return { ...item, translation: t };
     });
   }

apps/api/src/domains/operations/i18n/i18n.service.ts

@@ -1,8 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { PrismaService } from '../../../shared/prisma/prisma.service';
-import { DEFAULT_LOCALE } from '@thebet365/shared';
-
-const FALLBACK_ORDER = ['en-US', 'zh-CN', 'ms-MY'];
+import { resolveTranslationFallback } from '@thebet365/shared';
 
 @Injectable()
 export class I18nService {
@@ -10,7 +8,7 @@ export class I18nService {
 
   async getMessages(locale: string) {
     const messages = await this.prisma.i18nMessage.findMany({
-      where: { locale: { in: [locale, ...FALLBACK_ORDER] } },
+      where: { locale: { in: [locale, 'en-US', 'zh-CN', 'ms-MY'] } },
     });
 
     const byKey: Record<string, Record<string, string>> = {};
@@ -21,10 +19,8 @@ export class I18nService {
 
     const result: Record<string, string> = {};
     for (const [key, locales] of Object.entries(byKey)) {
-      result[key] =
-        locales[locale] ||
-        FALLBACK_ORDER.map((l) => locales[l]).find(Boolean) ||
-        key;
+      const resolved = resolveTranslationFallback(locales, locale);
+      result[key] = resolved || key;
     }
     return result;
   }