forEachGlyphAdvance
fun forEachGlyphAdvance(bytes: ByteArray, action: (advanceWidth: Double, isWordSpace: Boolean) -> Unit)
Invoke action once per glyph with its advance width (1/1000 em) and word-space flag, WITHOUT resolving any glyph outline or allocating a TextGlyph list. The fast path for advance/measurement (text positioning, width sums) where glyph shapes aren't needed — used by the renderer's advance calc, text extraction, and redaction layout.