feat(browser): migrate to CloakBrowser for browser emulation and streamline dependency management

- Replace Playwright-based browser emulation with CloakBrowser as default
- Update config to support CloakBrowser options and humanization presets
- Refactor browser helper to use CloakBrowser context and remove cf_clearance dependency
- Update Dockerfile, entrypoint, and update scripts to install CloakBrowser runtime
- Ensure CloakBrowser kernel is pre-installed during local setup and dependency updates
- Add tests for CloakBrowser integration and legacy compatibility

docker/update.sh

@@ -80,6 +80,10 @@ function install_backend_and_download_resources() {
                 cp /tmp/requirements.txt.backup /app/requirements.txt
                 return 1
             fi
+            INFO "正在更新 CloakBrowser 浏览器内核"
+            if ! ${VENV_PATH}/bin/python -m cloakbrowser install; then
+                WARN "CloakBrowser 浏览器内核更新失败，后续首次使用时可能重新下载"
+            fi
             INFO "依赖更新成功"
         else
             INFO "依赖无变化，跳过依赖更新"