feat(nix-darwin): Install and configure container/security tools bundle

Install a bundle of container and security tools currently installed via Homebrew:

Container Tools:
- `cosign` - Container signing and verification
- `crane` - Container registry interaction
- `dive` - Docker image layer explorer

Security Tools:
- `gitleaks` - Detect secrets in git repos
- `trivy` - Vulnerability scanner (if available)
- `sops` - Secrets management (if available)

These are currently in:
- `/usr/local/Cellar/`