feat(stage-layouts): simplify mobile stage controls (#2472)

Signed-off-by: RainbowBird <git@luoling.moe>

apps/stage-web/src/pages/index.vue

@@ -1,7 +1,6 @@
 <script setup lang="ts">
 import Header from '@proj-airi/stage-layouts/components/Layouts/Header.vue'
 import InteractiveArea from '@proj-airi/stage-layouts/components/Layouts/InteractiveArea.vue'
-import MobileHeader from '@proj-airi/stage-layouts/components/Layouts/MobileHeader.vue'
 import MobileInteractiveArea from '@proj-airi/stage-layouts/components/Layouts/MobileInteractiveArea.vue'
 import workletUrl from '@proj-airi/stage-ui/workers/vad/process.worklet?worker&url'
 
@@ -210,7 +209,6 @@ const cursorPosition = computed(() => ({
       <!-- header -->
       <div class="px-0 py-1 md:px-3 md:py-3" w-full gap-2>
         <Header class="hidden md:flex" />
-        <MobileHeader class="flex md:hidden" />
       </div>
       <!-- page -->
       <div relative flex="~ 1 row gap-y-0 gap-x-2 <md:col">