A horizontal or vertical glyph sat beside its line on a fixed side, so a
dimension placed on that side drew its value box on top of the glyph.
A glyph that would overlap a dimension's value now goes to the other side
of its line, or steps along it when both sides are taken.
The scenario `glyphs` check also fails when a glyph overlaps a dimension
value; constraint_glyphs_clear_of_dimensions covers it.
Fixes#175
Co-Authored-By: Claude Opus 5.5 <[email protected]>
