The canvas drew an underline (and a strikethrough) as one rectangle per
glyph; where two anti-aliased edges met at a fractional pixel they left
a lighter seam between the letters. Contiguous bars of the same colour
and position are merged into one, as the PDF export already does.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Conflict: crates/idml/src/import.rs: kept #230's Underline/StrikeThru colour line (Text Color resets) and #83's tint() helper
Conflict: ROADMAP.md: kept the chain's Text engine line and added #230's FID2 line