feat: Add i18n with 7 languages (DE, EN, ES, FR, AR, RU, PL)

- Added vue-i18n with language switcher in header
- Flag icons with language codes dropdown
- RTL support for Arabic
- Translated all navigation, auth, and module labels
- Language preference saved to localStorage

node_modules/@intlify/shared/index.js

@@ -0,0 +1,7 @@
+'use strict'
+
+if (process.env.NODE_ENV === 'production') {
+  module.exports = require('./dist/shared.prod.cjs')
+} else {
+  module.exports = require('./dist/shared.cjs')
+}