remove read_only_rootfs config and add more examples for code-interpreter

[Pangjiping]

Summary

• Remove the security option read_only_rootfs from the server, this will prevent the platform from injecting the execd binary.
• Add multi-language execution examples for the code interpreter

Testing

• Not run (explain why)
• Unit tests
• Integration tests
• e2e / manual verification

Breaking Changes

• None
• Yes (describe impact and migration path)

Checklist

• Linked Issue or clearly described motivation
• Added/updated docs (if needed)
• Added/updated tests (if needed)
• Security impact considered
• Backward compatibility considered

[hittyt]

LGTM