replace screenshot pipeline and update admin

app.py

@@ -33,7 +33,6 @@ from realtime.socketio_handlers import register_socketio_handlers
 from realtime.status_push import status_push_worker
 from routes import register_blueprints
 from security import init_security_middleware
-from services.browser_manager import init_browser_manager
 from services.checkpoints import init_checkpoint_manager
 from services.maintenance import start_cleanup_scheduler
 from services.models import User
@@ -199,7 +198,7 @@ def cleanup_on_exit():
     except Exception:
         pass
 
-    logger.info("- 关闭浏览器线程池...")
+    logger.info("- 关闭截图线程池...")
     try:
         shutdown_browser_worker_pool()
     except Exception:
@@ -278,15 +277,6 @@ if __name__ == "__main__":
     except Exception as e:
         logger.warning(f"警告: 加载并发配置失败,使用默认值: {e}")
 
-    logger.info("正在初始化浏览器管理器...")
-    try:
-        from services.browser_manager import init_browser_manager_async
-
-        logger.info("启动浏览器环境初始化（后台进行，不阻塞服务启动）...")
-        init_browser_manager_async()
-    except Exception as e:
-        logger.warning(f"警告: 启动浏览器初始化失败: {e}")
-
     logger.info("启动定时任务调度器...")
     threading.Thread(target=scheduled_task_worker, daemon=True, name="scheduled-task-worker").start()
     logger.info("✓ 定时任务调度器已启动")
@@ -305,7 +295,7 @@ if __name__ == "__main__":
     except Exception:
         pool_size = 3
     try:
-        logger.info(f"初始化截图线程池（{pool_size}个worker，按需启动浏览器，空闲5分钟后自动关闭）...")
+        logger.info(f"初始化截图线程池（{pool_size}个worker，按需启动执行环境，空闲5分钟后自动释放）...")
         init_browser_worker_pool(pool_size=pool_size)
         logger.info("✓ 截图线程池初始化完成")
     except Exception as e: