[SPIKE] Plan support for omarchy plugins

### Feature Description

Omarchy has hundreds of plugins in its catalog, and they are all in QML and quickshell-compatible. So we should consider adding support for omarchy plugins within DMS itself.

The spike:
- Determine how complex the omarchy plugin surface area is, and what components we'd have to create to make a compatible API
- Determine how we should expose omarchy plugin registry through the DMS CLI/API and UI
- Find and link the omarchy plugin manifest specification so we can support parsing it

### Use Case

It would gain an easy way to add hundreds of new plugins to DMS installations

### Compositor(s)

All compositors

### If Other, please specify

_No response_

### Proposed Solution

_No response_

### Alternatives/Existing Solutions

_No response_

Start by investigating the omarchy plugin surface and locating its plugin manifest specification. Then review the DMS CLI/API and UI entry points to determine how the registry could be exposed and what compatibility components would be needed. Done means documenting the surface-area complexity, required components, registry exposure, and linking the manifest specification.

Written by the indexing model from the issue text.