fix: show theme and font size controls before font families load

Move the v-if guard from the outer FontChange wrapper to only the font-family
selects, so ThemeSwap and the font-size select are always visible in the modal
even before userSettings.fontFamilies resolves asynchronously.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/FontChange.vue

@@ -15,8 +15,8 @@ const fontSizes = Array.from({ length: 7 }, (_, i) => `${9 + i * 2}pt`)
 </script>
 
 <template>
-  <div class="font-change" v-if="sortedFontFamilies.length > 0">
-    <div>
+  <div class="font-change">
+    <div v-if="sortedFontFamilies.length > 0">
       <label for="title-font" class="font-label">t</label>
       <select
         id="title-font"