Add Arabic language option to all locale files and support proper Arabic text display in terminal

- Added "ar" (Arabic) to the languages section in all translation JSON files in the locales directory.
- Implemented Arabic text reshaping and bidi support in main.py using arabic_reshaper and python-bidi for correct RTL display in terminal when Arabic is selected.

locales/zh_cn.json

@@ -35,6 +35,7 @@
         "bypass_token_limit": "绕过 Token 限制"
     },
     "languages": {
+        "ar": "阿拉伯语",
         "en": "英语",
         "zh_cn": "简体中文",
         "zh_tw": "繁体中文",