The shell tool output line was wrapping because update_tool_output_line
clipped the content without reserving space for the suffix that gets
appended later (line count + timing info).
Added suffix_overhead of 30 chars for shell tools to reserve space for:
- " (9999 lines)" = ~13 chars
- " | 99999 ◉ 999ms" = ~17 chars
This ensures the complete line fits within terminal width without wrapping.
c6df75d886