Fix tsk list: pad id with spaces instead of tab
The tab separator between id and title rendered as zero spaces on
terminals where the tab stop happened to land on the column right after
the id (e.g. width=6 tab stops with `tsk-15`). Replace with fixed-width
space padding so the title column lines up regardless of tab stops.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>