cli to build image for openshell sandboxes

[feloy]

The purpose of the cli openshell-image-builder is to help build container images which can be used as image for openshell sandboxes.

The OpenShell currently provides a set of images at https://github.com/NVIDIA/OpenShell-Community

The goal of this project is to build images similar to the ones provided by OpenShell, but configurable based on a kaiden's workspace.json file, and containing the minimal necessary.

The images will be built on a base image:

• Ubuntu
• Fedora
• Hummingbird
• UBI
• openshell-base (to be built)
• any other (based on a set of requisites)

An --agent flag installs the agent in the container:

• claude code
• opencode

The parts of workspace.json supported are:

• features: devcontainers features to install during image build
• skills: skills to copy in the image during image build
• env vars to declare in the image (if necessary for user)
• authorized hosts
• mcp services
• ...

The policy.yaml file added to the image will be adapted to the agent:

• claude code
• opencode

and inference provider:

• anthropic
• Vertex AI
• ollama (opencode only)
• openai
• openai compatible

Default configuration files for the agent will be added in the home:

• claude code
• opencode