TABLE output formatted every column value with format!("{value:<width$}"),
which only sets a minimum width. Target is free-form/user-controlled and
is the first default table column, so a long target label pushed every
later column out of alignment while numeric/measurement columns stayed
correct.
Add a table-only truncation for Column::Target: labels within
table_width() (18) render unchanged; longer labels keep a
character-boundary-safe prefix and end with "..." so the rendered cell
is exactly 18 characters. This is scoped to format_table_cell's Target
case only, so it cannot silently shorten any measurement/data column.
CSV, TSV, and JSONL are untouched and keep emitting the full,
untruncated target label.
Nils Andreas Svee