dsh-accounts-ui: Add a Settings Panel Entry Point for dsh-accounts

`dsh-accounts-ui` is a transitional tool that provides a native UI rendering entry point for the `dsh-accounts` plugin. By registering a settings section, it integrates account management into the DSH settings panel, supporting list display, CRUD operations, and secure local data read/write. This plugin has been superseded by an upstream PR and is only intended as a temporary patch; when installing it, take care to avoid conflicts with the upstream version.