移除API密钥验证相关的代码和样式，删除无用的图片文件，优化进度指示器的样式和动画效果，调整设置面板的布局，简化API密钥管理功能，提升用户体验。

models/base.py

@@ -45,7 +45,3 @@ class BaseModel(ABC):
     def get_model_identifier(self) -> str:
         """Return the model identifier used in API calls"""
         pass
-
-    def validate_api_key(self) -> bool:
-        """Validate if the API key is in the correct format"""
-        return bool(self.api_key and self.api_key.strip())

models/mathpix.py

@@ -211,16 +211,6 @@ class MathpixModel(BaseModel):
         """
         return "mathpix"
 
-    def validate_api_key(self) -> bool:
-        """
-        Validate if the API key is in the correct format (app_id:app_key).
-        """
-        try:
-            app_id, app_key = self.api_key.split(':')
-            return bool(app_id.strip() and app_key.strip())
-        except ValueError:
-            return False
-
     def _format_response(self, result: Dict[str, Any]) -> str:
         """
         Format the Mathpix API response into a readable string.