Add 'karapace new' to generate a manifest from templates or prompts.
Add 'karapace tui' to launch the terminal UI.
Improve env-id resolution errors in non-JSON output with suggestions.
Add dialoguer and toml as CLI dependencies.
- Run cargo fmt on skip_if_root() blocks
- Add skip_if_root() to migrate_atomic_version_unchanged_on_write_failure
- Add libc dev-dependency to karapace-store for root check
- Remove explicit shell: sh from container rustup steps (OCI exec
can't find sh in PATH; default run shell works)