GitHub Codespaces Prebuilds and VS Code Remote Containers: Custom Feature Persistence Across Codespace Starts

The goal is to clarify whether custom devcontainer features referenced in a codespace's devcontainer.json are re-applied from the feature registry on each startup when a GitHub Codespaces prebuild is active, or whether they remain fixed to the version baked into the prebuild image. A key constraint is that prebuild availability and feature baking behavior are not explicitly documented, creating uncertainty for maintainers who depend on feature updates without regenerating prebuilds. The interaction between the prebuild snapshot lifecycle and the Remote Containers feature resolution mechanism determines the persistent state of the development environment across codespace restarts.

• Does the prebuild pipeline re-evaluate devcontainer.json features on every codespace start, or does it prioritize the cached image configuration?
• When a custom feature is updated in its upstream registry, does a new codespace launch with an existing prebuild automatically reflect the change, or must a new prebuild be triggered?
• How does feature version conflict resolution behave when the devcontainer.json specifies a feature version that differs from the prebuild's baked version?