fix: align cashu nutzap icon with reaction icons in notifications

The nutzap gallery in MultiSetCompose used WidthAuthorPictureModifier
(55dp, flush-right) for its cashu icon column, while the like/boost
reaction galleries above it use NotificationIconModifier (55dp with a
5dp end inset). That left the cashu glyph sitting ~5dp further right
than the reactions it stacks under. Switch the cashu Box to the same
NotificationIconModifier so the icons line up.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011qQdaD3DHRQNDKe2BUnEiM

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/MultiSetCompose.kt

@@ -451,7 +451,10 @@ fun RenderNutzapGallery(
 
     Row(Modifier.fillMaxWidth()) {
         Box(
-            modifier = WidthAuthorPictureModifier,
+            // Reuse the reaction galleries' icon column (55dp wide with a 5dp end
+            // inset) so the cashu glyph lines up with the like/boost icons above
+            // it, instead of sitting flush-right like the lightning ZappedIcon.
+            modifier = NotificationIconModifier,
         ) {
             Icon(
                 imageVector = CustomHashTagIcons.Cashu,