[docker/cli] Run Dev Containers inside Docker Sandboxes for AI coding agent workflows

### ROOT CAUSE The issue arises because the Docker sandbox feature lacks native support for Dev Containers, which require specific configuration (e.g., devcontainer.json) and build processes. When using `docker sandbox`, the default container lacks Dev Container features, leading to inconsistencies with standard development environments. ### CODE FIX ```bash # Modify the Docker CLI to support Dev Container builds in sandboxes # Add a new command to build and run a Dev Container sandbox: docker sandbox dev --devcontainer-dir ./devcontainer . # Under the hood, this uses the devcontainer build process: # 1. Build the Dev Container image from devcontainer.json # 2. Configure sandbox-specific ephemeral storage # 3. Start the container with temporary volumes # Example devcontainer.json configuration (minimal): { "name": "AI Sandbox", "build": "source", "context": "..", "forwardPorts": [7835, 7935], "extensions": ["ms-vscode.cpptools"] } ``` This solution extends the `docker sandbox` command to handle Dev Container configurations by integrating the `docker build` process with sandbox ephemeral storage.