fix(cli): harden non-install command output mode rendering

[ian-pascoe]

Summary

• harden non-install command rendering so progress-backed flows use progress-safe line/status emission and skip zero-work progress output
• enforce strict output-style split (Rich only when both stdout/stderr are TTY; otherwise plain), while keeping raw payload/script outputs undecorated
• expand CLI tests for output-style contracts, update-output planning behavior, and zero-work progress handling

Validation

• rustup run stable cargo fmt --all
• rustup run stable cargo clippy -p crosspack-cli --all-targets -- -D warnings
• rustup run stable cargo test -p crosspack-cli
• cargo run -q -p crosspack-cli --bin crosspack -- update
• script -q -c "cargo run -q -p crosspack-cli --bin crosspack -- update" /dev/null