Feature: Enable Docker-in-Docker Support for Integration Tests 🐳

[GordonBeeming]

Description

Currently, copilot_here runs as an isolated container. This is great for security, but it prevents us from running integration tests that need to spin up their own containers (like a temporary database or a mock API) from inside the environment.

We need to implement "Docker in Docker" (DinD) or "Docker outside of Docker" (DooD) support. This will allow the copilot_here container to interact with a Docker daemon to build, run, and manage other containers.

Benefits

• ✅ Self-Contained Testing: We can run complex integration tests entirely within the copilot_here instance without needing to manually set up external dependencies on the host machine.
• ✅ CI/CD Compatibility: Makes it much easier to use copilot_here in CI pipelines where we might need to spawn sibling containers for testing logic.
• ✅ Improved Dev Experience: Contributors can run the full test suite with a single command inside the container, ensuring their environment matches the CI environment exactly.