- Extend prepare_ssh_key_files() with optional uid/gid parameters
- Call os.chown on created files when uid/gid are provided
- Gracefully handle PermissionError if API process is not root
- In start_instance, extract container user UID/GID from manifest
- Pass container UID/GID when preparing instance-level SSH key mounts
- Legacy clone-mode SSH keys continue to use root (0,0)
- Add unit tests for prepare_ssh_key_files ownership logic
- Keep apply_ssh_permissions() as fallback for cases where host chown fails
Quality gates: pytest 239 passed (6 pre-existing failures), tsc --noEmit clean
Alex Blank