fix(math): center inline equations on the text line

The equation image is taller than a text line, and the paragraph FlowRow
top-aligned its items, so equations hung below the baseline. Center items
on the cross axis (itemVerticalAlignment) so the equation sits centered
on the line; no-op for the common all-text row where every item is the
same height.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/RichTextViewer.kt

@@ -395,6 +395,10 @@ fun RenderTextParagraph(
     FlowRow(
         modifier = modifier,
         horizontalArrangement = Arrangement.spacedBy(spaceWidth),
+        // Center items on the cross axis so a taller item (an equation, whose image
+        // is taller than a text line) sits centered on the line instead of hanging
+        // below the baseline. No-op for the common all-text row.
+        itemVerticalAlignment = Alignment.CenterVertically,
     ) {
         paragraph.words.forEach { word ->
             renderWord(word)