fix: text compose papercuts (#270)

* make fixes

* cleanup

js/desktop/src/lib/immersive-text.ts

@@ -0,0 +1,7 @@
+/** Font scale for short messages shown as large centered text. Shared by the
+ *  composer and the posted view so editing matches the final render. */
+export function getImmersiveTextStyle(length: number) {
+  if (length < 30) return { size: 'text-5xl', weight: 'font-semibold' };
+  if (length < 70) return { size: 'text-3xl', weight: 'font-semibold' };
+  return { size: 'text-2xl', weight: 'font-normal' };
+}