[docs:gsoc26] Documentation for MassCommand feature

This issue is created to track documentation for issues

1. #1344
2. #1345
3. #1347
4. #1348
5. #1349

and add static media files (such as images or GIFs) to the docs branch after the complete implementation of each feature, to visually document the final workflow and functionality.

Documentation scope to preserve

The documentation should cover the dedicated admin Run Command workflow, including target selection, confirmation, command selection, and execution monitoring.

The documentation should cover the Command Operations or MassCommand history page, including how users can inspect past mass command operations and per-device execution results.

The documentation should cover the device-list admin action entry point and explain how selected devices flow into the mass command workflow.

The documentation should cover the device detail command history integration, including how a command executed through a MassCommand links back to the parent operation.

The REST API documentation should include examples for confirmation, creation, listing, retrieving details, pagination of per-device results if implemented, and deletion behavior once finalized.

The documentation should explain permission and multi-tenancy behavior, including all devices, organization, location, device group, and manual device selection scopes.

Static media or GIFs should show the final admin workflow after the UI and API behavior are finalized.