fix: move v-if to SelectIcon to avoid as-child without child element

When loading is true, the inner <i> was removed leaving SelectIcon
with as-child but no child to forward attributes to. Move the guard
to SelectIcon itself so it unmounts entirely when loading.

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

src/components/input/SingleSelect.vue

@@ -37,9 +37,8 @@
         <slot v-else name="icon" />
         <SelectValue :placeholder="label" class="truncate" />
       </div>
-      <SelectIcon as-child>
+      <SelectIcon v-if="!loading" as-child>
         <i
-          v-if="!loading"
           class="icon-[lucide--chevron-down] shrink-0 px-3 py-2 text-muted-foreground"
         />
       </SelectIcon>