feat(compose): add persistent Docker Compose support

[RobertDeRose]

Type of Change

• New feature
• Bug fix
• Breaking change
• Documentation update

Motivation and Context

Inspired by the k8s' plugin implementation and container machines, this feels like the correct way to finally support docker-compose.yml workflows in an efficient way that doesn't require a full compose-to-container translation layer.

This adds container compose support backed by a persistent Linux container machine
running Docker Engine and the real Docker Compose CLI.

This provides a Docker-compatible Compose workflow without Docker Desktop while
keeping Compose state isolated inside a managed compose machine.

What Changed

• Added the container compose plugin.
• Automatically builds and provisions the bundled Compose machine image.
• Persists the compose machine and its Docker data across invocations.
• Forwards Compose arguments unchanged to /usr/bin/docker compose.
• Added container machine start for generic stopped-machine recovery.
• Added optional Docker socket access through --socket-path.
• Added machine DNS aliases and published-port diagnostics.
• Added configurable CPU, memory, and idle-shutdown settings.
• Added ownership tokens and safe orphan/cancellation handling.
• Added daemon-root-aware configuration loading.
• Documented lifecycle, filesystem, networking, socket, and configuration behavior.

Important Behavior

• container compose down removes Compose resources but does not delete or stop the machine.
• All Compose projects share the persistent compose machine.
• Bind mounts must be below the mounted macOS home directory.
• Published ports are reachable through the Compose machine address, not automatically through macOS loopback.
• --socket-path reports the endpoint only; it never starts the machine.
• Configuration changes require restarting the container service.

Testing

• Tested locally
• Added/updated tests
• Added/updated docs

Validation completed:

• 814 unit tests across 91 suites passed.
• Machine lifecycle integration tests passed, including first boot and starting a stopped machine.
• Warnings-as-errors build passed.
• git diff --check passed.

Related Issues and Discussions

• compose support? #55 — “compose support?” — closed request for Docker Compose file support.
• [Request]: Support Docker Compose Files #235 — “Support Docker Compose Files” — closed duplicate/related request.
• Discussion Creating Docker Compose for Container #320 — discusses implementing Compose as a plugin.
• Discussion Expanding Support for Plugins #1410 — ongoing plugin/API compatibility discussion.
• PR Add Compose #239 and PR Compose functionality using familiar docker-compose syntax for container #398 — prior Compose-related implementations.