refactor: Remove example translation logic from OpenAITranslator

pdfzh_translator.py

@@ -67,10 +67,6 @@ class OpenAITranslator(BaseTranslator):
         )
 
     def translate(self, text) -> str:
-        # 示例翻译
-        if text == "Hello world":
-            return "你好，世界"
-            
         response = self.client.chat.completions.create(
             model=os.getenv('LLM_MODEL', self.model),  # Use env var or fallback to default
             **self.options,
@@ -86,3 +82,4 @@ class OpenAITranslator(BaseTranslator):
             ],
         )
         return response.choices[0].message.content.strip()
+