fix: restore icon color on button elements in header

<button> gets color:ButtonText from the browser UA stylesheet, making
SVG stroke="currentColor" render black. Add text-base-content to
inherit the DaisyUI theme color like the <a>-based router-links do.

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

src/components/HeaderNote.vue

@@ -32,7 +32,7 @@ defineProps<{ user: string; repo: string }>()
       </svg>
     </router-link> -->
 
-    <button class="btn btn-ghost btn-circle" onclick="font_modal.showModal()">
+    <button class="btn btn-ghost btn-circle text-base-content" onclick="font_modal.showModal()">
       <svg
         xmlns="http://www.w3.org/2000/svg"
         class="icon icon-tabler icons-tabler-outline icon-tabler-typography"

src/components/HomeButton.vue

@@ -6,7 +6,7 @@ const goHome = () => router.push({ name: "Home" })
 </script>
 
 <template>
-  <button class="btn btn-ghost btn-circle btn-lg" @click="goHome">
+  <button class="btn btn-ghost btn-circle btn-lg text-base-content" @click="goHome">
     <img src="/favicon.png" alt="Remanso icon" class="remanso-logo" />
   </button>
 </template>