Added 17 new test functions covering:
- DockerHost.ToFrontend() with variants for empty display name, swarm,
services, tasks, and command status
- Host.ToFrontend() with display name fallback logic
- CephCluster.ToFrontend() including empty pools/services case
- ReplicationJob.ToFrontend() including nil time handling
- DockerServiceUpdate.ToFrontend()
- DockerContainer.ToFrontend() for Podman info
Coverage improved from 33.0% to 44.0% in internal/models package.