## What changed
- Use Ratatui-compatible terminal widths throughout TUI layout, preserving
full-width counters for long lines.
- Wrap and truncate on grapheme boundaries so halfwidth kana sound marks and
emoji sequences stay intact.
- Apply the corrected sizing to text input, selection popups, status and
history cells, Markdown, hyperlinks, and scrollable cloud diffs.
## Testing
- Add focused unit and snapshot coverage for wrapping, truncation, cursor and
mask alignment, popup columns, status output, session headers, Markdown
tables, process output, and scrollable diffs.
GitOrigin-RevId: 294ec0bcff743c6bb16d55ec26308524ce741879
