fix(cli): ignore broken pipe during status line cleanup

[gaoflow]

Summary

• ignore BrokenPipeError while StatusLine.stop() writes/flushed terminal cleanup output
• always restore the wrapped print and input builtins during status line shutdown
• add a regression test for closed stdout pipes during cleanup

Closes #1150

Tests

• uv run pytest tests/test_status_line.py::TestStatusLineInit::test_stop_ignores_broken_pipe_and_restores_builtins -q
• uv run pytest tests/test_status_line.py -q
• uvx --with tox-uv tox run -e lock
• uvx --with tox-uv tox run -e lint
• uvx --with tox-uv tox run -e unit -- tests/test_status_line.py

Notes

• uvx --with tox-uv tox run -e unit on this macOS machine reached 222 passed but failed two unrelated helper tests: test_is_in_snap_private_dir and test_parse_filename_snap_private. Those tests expect /tmp/job.yaml to remain under /tmp; on macOS Path.resolve() maps it under /private/tmp, so it no longer matches SNAP_PRIVATE_DIRS = ["/tmp"].

AI assistance was used under my direction.