Reapply "feat: 增强加载指示器处理逻辑，添加轮询策略以解决竞态条件"

Revert "feat: 增强加载指示器处理逻辑，添加轮询策略以解决竞态条件"

feat: 增强加载指示器处理逻辑，添加轮询策略以解决竞态条件

feat: Implement Camoufox browser instance manager with multiprocessing support