feat(security): add cache default extension for files without suffix

app/chain/recommend.py

@@ -116,6 +116,10 @@ class RecommendChain(ChainBase, metaclass=Singleton):
         sanitized_path = SecurityUtils.sanitize_url_path(url)
         cache_path = settings.CACHE_PATH / "images" / sanitized_path
 
+        # 没有文件类型，则添加后缀，在恶意文件类型和实际需求下的折衷选择
+        if not cache_path.suffix:
+            cache_path = cache_path.with_suffix(".jpg")
+
         # 确保缓存路径和文件类型合法
         if not SecurityUtils.is_safe_path(settings.CACHE_PATH, cache_path, settings.SECURITY_IMAGE_SUFFIXES):
             logger.debug(f"Invalid cache path or file type for URL: {url}, sanitized path: {sanitized_path}")