Add a bind to move the workspaces up and down.

[Yocraft-2000]

Summary

Added workspace-move-up and workspace-move-down binds.

Motivation

These binds exist in niri and I miss them in umbriel.

Type of Change

• Bug fix
• New feature
• Breaking change
• Refactoring
• Build / packaging
• Documentation

Related Issue

None.

Testing

The trailing empty workspace is ignored.

Manual Coverage

• Tested in a nested Umbriel session
• Tested in a native Umbriel session
• Tested with multiple monitors
• Tested with a scaled output
• Tested with native Wayland applications
• Tested with X11 applications through xwayland-satellite
• Tested with the scrolling layout
• Tested with the dwindle layout

Screenshots / Videos

Checklist

• This PR is ready for review, or it is marked as Draft.
• I read and followed the relevant guidance in CONTRIBUTING.md.
• I initialized and updated the SceneFX submodule where required.
• I ran just format, or this PR has no C++ changes.
• I ran the relevant build, test, lint, or verification commands, or explained why they were not run.
• I functionally verified compositor behavior where automated checks are insufficient.
• I self-reviewed the changes.
• I checked for new warnings or errors.
• I updated docs/ and examples/config.toml, or this PR does not change user-facing configuration or behavior.
• I used canonical names for config keys, IPC actions, paths, and identifiers.

Additional Notes

[Yocraft-2000]

Allowing the trailing workspace to move since that's how it works in niri.

[Ly-sec]

Hey @Yocraft-2000 , looks good overall, but I think this needs a couple of changes before merging:

• Add the new actions to groupForAction() so they appear under Workspaces instead of System in the cheatsheet.
• Add a regression check covering workspace order, names, and the dynamic trailing empty workspace.
• Please confirm the intended behavior when moving the trailing empty workspace upward, since it currently leaves no empty workspace at the bottom until another reconciliation event.

The swap and metadata refresh approach otherwise looks sensible.

Also of course the conflicts need to be resolved :).