Multi-line bash commands (e.g., for loops with newlines) were being passed
as single "lines" to renderOutputBlock. Since visibleWidth() treats newlines
as width 0, truncateToWidth() calculated incorrect truncation points. The
result was rendered lines with embedded newlines that exceeded terminal width,
causing "Rendered line N exceeds terminal width" crashes.
Split section lines by newlines before processing so each line gets properly
truncated and wrapped with box borders.
can1357
2ae12a7cee