refactor: 调整i18n文本目录结构

- 目录调整: i18n文本由单文件改为多文件
- 组件修改: 对应组件内的文本key做出对应修改
- WIP: 其他语言适配逐步完成...

src/plugins/i18n.ts

@@ -1,17 +1,18 @@
 import { createI18n } from 'vue-i18n'
-import en from '@/locale/en.json'
+import en from '@/locale/en'
 import ru from '@/locale/ru.json'
 import sp from '@/locale/sp.json'
-import zh from '@/locale/zh.json'
+import zh from '@/locale/zh'
 
-export default createI18n({
+type MessageSchema = typeof zh
+type AvailableLocales = 'zh' | 'en'
+
+export default createI18n<[MessageSchema], AvailableLocales>({
   legacy: false,
   locale: 'zh',
-  fallbackLocale: 'en',
+  fallbackLocale: 'zh',
   messages: {
     zh,
     en,
-    ru,
-    sp,
   },
 })