Setup Sandcastle

One-time guided setup. Installs Sandcastle and configures an isolated sandbox provider so agents can run in parallel without stepping on each other.

Workflow

Step 1 -- Detect environment

• Check if sandcastle is already installed (npx sandcastle --version or check package.json)
• Detect available container runtimes: Docker, Podman, or Firecracker
• Check if the project is TypeScript/JavaScript (Sandcastle is a TS library)
• Check for existing sandbox or container configuration

Present findings to user before proceeding.

If detection is ambiguous, use AskUserQuestion to clarify:

• If no container runtime detected: explain that Docker, Podman, or Firecracker is required, ask which they'd like to install, and link to install docs
• If the project is not JS/TS: explain Sandcastle is a TS library, ask if they still want to proceed (it can still orchestrate non-JS agent tasks inside containers)