dsh-mod-manager: Enable and disable third-party plugins on the DSH Web settings page

`dsh-mod-manager` is a third-party plugin manager for the DeepSeek Harness Web profile, designed to simplify plugin enabling and disabling and eliminate the need for manual editing of `cordis.patch.yml`. Licensed under the MIT License, its core features include centrally displaying the status of installed plugins on the settings page, automatically discovering third-party bundles installed via `dsh plugin`, and supporting one-click toggling of plugins. It implements hot reloading via the Harness patch watcher, typically eliminating the need to restart the service. The manager automatically excludes core bundles and itself, while preserving unmanaged configurations and custom items in `config.mods`. It is compatible with empty files or purely commented files. Installation requires Node.js...