chore(m177): put 3.4's DONE marker on the bullet the gate reads

`spec.dimensions` matches per bullet LINE, and 3.4's marker sat on a
continuation line — the only one of the twenty-five whose citation wraps. The
row was DONE; the gate could not see it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>