Add lobe-i18n setup and translation scripts and update translation files for consistency (#1751)

* refactor: convert translation files from TS to JSON format

* feat: add lobe-i18n setup and translation scripts

* chore: update translation files for consistency

* chore: refine translations in ja_JP.json for natural phrasing

* refactor: revert locale file names to original simpler format (e.g., en_US → en)

.i18nrc.cjs

@@ -0,0 +1,11 @@
+// This file is intentionally kept in CommonJS format (.cjs) 
+// to resolve compatibility issues with dependencies that require CommonJS.
+// Do not convert this file to ESModule format unless all dependencies support it.
+const { defineConfig } = require('@lobehub/i18n-cli');
+
+module.exports = defineConfig({
+  entry: 'src/locales/en.json',
+  entryLocale: 'en',
+  output: 'src/locales',
+  outputLocales: ['zh', 'ru', 'ja'],
+});