Support devcontainer.json in Cloud Environments (and local Docker)

Cloud Environments currently only let you configure env vars and a bash setup script. There's no way to reuse a repo's existing `.devcontainer/devcontainer.json` or point at a prebuilt container image.

I already have a devcontainer that Codespaces and VS Code use for my toolchain. To get the same setup in a Claude environment I have to rewrite all of it as a bash script and keep the two in sync manually.

Would be great if Claude Code could just read `devcontainer.json` from the repo (or let me specify a base image) so the environment lives in one place instead of being duplicated in a setup script. Ideally this works both for cloud environments and locally via Docker.

Start by locating the cloud-environment configuration and the bash setup-script handling in the repository, then inspect the existing .devcontainer/devcontainer.json described in the issue. Compare the current cloud flow with local Docker usage and define how a repository devcontainer or base image would be selected. Done means the same devcontainer configuration can drive both cloud environments and local Docker without duplicating setup steps.

Scritto dal modello di indicizzazione a partire dal testo della issue.