Implement stackbox rebuild

[abhibongale]

Implement the stackbox rebuild command that rebuilds just the Ironic image and restarts only the affected containers. This enables the fast iteration workflow: make code changes → rebuild (< 2 min) → test.

Goals

• Implement rebuild command functionality
• Rebuild only Ironic image
• Restart only Ironic containers
• Preserve database and other state
• Show rebuild progress
• Measure and display rebuild time

Tasks

• Implement rebuild command (remove stub)
• Rebuild Ironic image
• Restart ironic-api container
• Restart ironic-conductor container
• Preserve database/RabbitMQ containers
• Show progress during rebuild
• Measure total rebuild time
• Add --service flag for other services
• Test complete rebuild workflow

Acceptance Criteria

• stackbox rebuild runs successfully
• Ironic image is rebuilt
• Only Ironic containers restart
• Database data is preserved
• Node enrollments are preserved
• Total time < 2 minutes
• Can run tests immediately after
• Supports rebuilding specific services