Add optional Claude Code features

Add a claude code question that adds:-

Primary fetures:
- installs claude code into the devcontainer
- enables auto-mode and dangerously-skip-permissions option
- adds gh and glab tools and PAT management to give claude restricted access to the specific repository
- entirely sandboxes claude from any other user credentials on the host
- refuses to run claude with these settings outside of the sandbox

Secondary features
- document in the main repo a workflow for using code as distilled from Matt Pocock's lecture https://youtu.be/-QFHIoCo-Ko?si=UwGHGjDHIQSB7q7 (or just reference https://github.com/mattpocock/skills?? - its not claude specific though)
- document how to use the sandbox and git PATs
- include useful skills to go with the above from https://github.com/mattpocock/skills