Function calculate_outline_transform 

fn calculate_outline_transform(
    glyph: Glyph,
    draw_props: DrawProps,
    hinting_instance: Option<&HintingInstance>,
) -> Affine

Calculate transform for outline glyphs.

This computes the final positioning transform for an outline glyph, taking into account:

• Glyph position within the run
• Run-space glyph positioning
• Y-axis flip (fonts use upside-down coordinate system)
• Hinting adjustments (snap y-offset to integer)