fix: replace incorrect rstrip('/v1') with endswith check to prevent URL truncation; add English README

- rstrip('/v1') strips individual chars from the set {'/', 'v', '1'}, which silently corrupts URLs
  (e.g. api.openai.com -> api.openai.co). Replaced all 5 occurrences with proper endswith('/v1')
  suffix removal in config_routes, text_client, openai_compatible, and image_api modules.
- Replace bare except clause with except Exception in history service.
- Add README_EN.md and language toggle links for internationalization.

Author: HisMax

README.md

@@ -1,5 +1,7 @@
 <div align="center">
 
+**中文 | [English](./README_EN.md)**
+
 <img src="images/2.png" alt="红墨 - 灵感一触即发 让创作从未如此简单" width="600"/>
 
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