fix(Popup): hide theme settings on external popup (as variables can't be accessed from there)

src/svelte-interface/pages/settings/theme.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import BackgroundSelector from "@/svelte-interface/components/themes/BackgroundSelector.svelte"
   import ThemeSelector from "@/svelte-interface/components/themes/ThemeSelector.svelte"
+  import { standalone } from "@/svelte-interface/utils/standalone.svelte"
   
   // backgrounds
   let selectedBackground = $state<string | null>(null);
@@ -11,6 +12,7 @@
 </script>
 
 <div class="py-4">
+  {#if !standalone}
     <button
       onclick={() => selectNoBackground()}
       class="w-full px-4 py-2 mb-4 text-[13px] dark:text-white transition rounded-xl bg-zinc-200 dark:bg-zinc-700/50">
@@ -24,4 +26,11 @@
       <BackgroundSelector isEditMode={editMode} bind:selectedBackground={selectedBackground} bind:selectNoBackground={selectNoBackground} />
       <ThemeSelector isEditMode={editMode} />
     </div>
+  {:else}
+    <div class="flex items-center justify-center w-full h-full">
+      <div class="text-lg">
+        Open SEQTA and use the embedded settings to access theme settings. 🫠
+      </div>
+    </div>
+  {/if}
 </div>