fix(driver): macOS/Linux 下载的 Chrome/Edge 驱动缺少执行权限导致运行失败

zipfile 解压不保留 Unix 执行位，extract 后 chmod 755；同时在启动检查
时对已下载但不可执行的旧驱动自动修复权限。

Co-Authored-By: Claude <noreply@anthropic.com>

src/managers/driver/WebDriverDownloader.py

@@ -360,6 +360,10 @@ class WebDriverDownloader:
                     break
             if not driver_file:
                 raise FileNotFoundError(f"未找到 web driver 文件 : {expected_name}")
+            # Ensure executable permissions on Unix systems (zipfile
+            # extraction does not preserve the execute bit).
+            if os.name != 'nt':
+                os.chmod(driver_file, 0o755)
             progress_callback(100, 100, 0.0, "解压完成")
             self.download_path.unlink()
             self._cleanup(driver_file)

src/managers/driver/WebDriverManager.py

@@ -111,6 +111,10 @@ class WebDriverManager:
             for driver_info in self.__driver_infos:
                 driver_path = self._getDriverPath(driver_info)
                 if driver_path and driver_path.exists() and driver_path.is_file():
+                    # Repair missing execute permission on Unix
+                    # (zip-extracted drivers from older versions).
+                    if os.name != 'nt' and not os.access(str(driver_path), os.X_OK):
+                        os.chmod(str(driver_path), 0o755)
                     driver_info.driver_path = driver_path
                     driver_info.driver_status = WebDriverStatus.INSTALLED