Docker Desktop

Install Docker Desktop on this machine. Follow these steps in order:

1. Detect my operating system and CPU architecture and tell me what you found.

2. Pick the install method for my OS:
   - macOS: Homebrew cask `docker-desktop`. If Homebrew is not installed, tell me and ask whether I want it installed from https://brew.sh first — wait for my answer before touching Homebrew.
   - Windows: WinGet package `Docker.DockerDesktop`.
   - Linux: Docker Desktop is not what you want here — stop and tell me; on Linux the usual choice is Docker Engine, which is a different install.

3. Check whether Docker Desktop is already installed. If it is, tell me the installed version and ask whether I want to upgrade or leave it as is.

4. Before running anything, show me the exact commands you intend to run and what they will download and from where, then wait for my approval.

5. After my approval, run the install, then verify it worked by reporting the installed version (open Docker Desktop, wait for it to finish starting, then `docker --version`) and show me the output.

Do not change any of my settings unless I ask.

After installation, guide me through:
- Review and accept the Docker Subscription Service Agreement on first launch
- Approve the privileged helper (macOS) or WSL 2 backend setup (Windows) when prompted
- Decide whether to sign in to Docker Hub
- Review resource limits (CPU/memory) and adjust for this machine