Display-mirror hybrid (docs/plan-harness-visibility.md §2): native tool
calls now show up in the shared sandbox terminal again via inert `# `-
prefixed comment lines (comment-prefix = anti-double-run/anti-escape),
mirroring only each command. Chat de-flooded to opener + final summary.
write_file mkdir -p parent dir so relative/absolute paths both work
(fixes the regression where script creation silently failed). ui.rs
fmt_line returns Vec<Line> splitting on \n so multi-line agent output
renders as an indented block instead of one garbled row.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>