dsh-groups: One-click group toggle for DSH plugins

dsh-groups is maintained by zyfsyx666 (workflow categorization, 2 stars on GitHub, MIT license, version 1.5.0). It compiles the list of bundles in `dsh.profile.bundles` into several named groups; clicking on the panel switches the entire group at once. Enabling a group acts as an addition, keeping only that group acts as an override, and disabling it acts as a subtraction; two groups can be enabled simultaneously. Groups marked with "persist" are automatically stacked in any configuration, while groups marked with "solo" do not stack. The card previews newly added, uninstalled, and to-be-disabled plugins, and creates a backup before writing to disk. Groups can be defined as agent presets (e.g., `group-<id>`), but presets only manage the agent plane; third-party plugins still require top-level group switches and a restart. Presets can only be changed when the session is empty. Plugins do not support hot reloading (requires `node>=22` and `dsh>=0.2.0-rc.1`). To install, clone via `git clone` to `~/.dsh/plugins-src`, register the profile, and run `pnpm install`; changes take effect after a restart. It runs with the permissions of the current dsh process; please check the source code and license before installing.