feat(ui): wire deferred Card tone and elevation variants

src/lib/components/ModelDownloader.svelte

@@ -62,7 +62,7 @@
 </script>
 
 <div class="flex flex-col items-center justify-center h-full px-8 animate-fade-in">
-  <Card classes="max-w-md w-full">
+  <Card classes="max-w-md w-full" elevation="raised">
     <div class="p-8 text-center">
       <div class="w-16 h-16 rounded-full bg-accent/10 flex items-center justify-center mx-auto mb-5">
         <svg class="w-8 h-8 text-accent" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5">

src/lib/pages/FilesPage.svelte

@@ -154,7 +154,7 @@
 
   <!-- Drop zone -->
   <div class="px-7 pb-3">
-    <Card>
+    <Card tone="subtle">
       <div
         class="flex flex-col items-center justify-center py-10 px-6 rounded-xl border-2 border-dashed m-3
           {isDragOver

src/lib/pages/HistoryPage.svelte

@@ -619,7 +619,7 @@
 
   <!-- Search -->
   <div class="px-7 pb-3">
-    <Card>
+    <Card tone="subtle">
       <div class="flex items-center gap-3 px-4 py-2.5">
         <Search size={16} class="text-text-tertiary flex-shrink-0" aria-hidden="true" />
         <input