The error-only logging default suppressed replay output, causing five
GTK tests to fail and two layer-shell tests to skip their assertions.
Set RUST_LOG=debug and GHOSTTY_LOG=stderr for the child app so both replay
output and capability detection are independent of inherited settings.
Document the harness logging contract without changing application defaults.
Test plan:
- cargo test -p ghostty-rs --all-features --test gtk_replay (7 passed)
- cargo clippy, cargo clippy --benches, cargo clippy --tests
- cargo +nightly fmt and repeat the clippy checks
Related-commit: 4fb9faa
ddidderr
62e1209b37