fix(colitur-x): detect the CSV header instead of assuming it

Skipping the first line unconditionally punished the obvious way to view
one month --

    colitur emit --format csv ... | grep '^2027-04' | colitur-x

-- by silently eating 1 April, because grep had already removed the
header the program still expected. A filter is exactly what this program
should compose with.

A header is the line beginning 'date,'; anything else is a day. Verified
all three ways: full year with header 365 rows from 01-01, a grepped
month without header 30 rows from 04-01, and the old head -1 incantation
still 30 rows.

0 files changed, 0 insertions, 0 deletions