Branch deploys for Terraform and Helm

Branch-based deployments now extend to Terraform and Helm Chart services backed by a GitHub repository. Configure branches under Settings > Build & Deploy, and each branch gets its own release channel so commits on staging, dev, or any other branch build and release independently. When you install the service in an environment, pick the branch channel that matches the environment's purpose. The same branch configuration is available through YAML and the CLI, and existing promotion pipelines continue to work alongside branch channels for cross-environment promotion.
