fix(context): share selected campus across layout

clinical-web/src/components/layout/Header.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, ref } from 'vue'
+import { computed } from 'vue'
 import { useRoute } from 'vue-router'
 
 import { useAppStore } from '@/stores/app'
@@ -7,9 +7,6 @@ import { useAppStore } from '@/stores/app'
 const route = useRoute()
 const appStore = useAppStore()
 
-const campuses = ['本部院区', '东院区', '西院区']
-const selectedCampus = ref(campuses[0])
-
 const pageTitle = computed(() => String(route.meta.title ?? '首页'))
 const pageGroup = computed(() => String(route.meta.group ?? '工作台'))
 </script>
@@ -23,8 +20,10 @@ const pageGroup = computed(() => String(route.meta.group ?? '工作台'))
     <span class="header-spacer" />
     <label class="campus-selector">
       <span class="campus-label">院区</span>
-      <select v-model="selectedCampus" aria-label="选择院区">
-        <option v-for="campus in campuses" :key="campus" :value="campus">{{ campus }}</option>
+      <select v-model="appStore.selectedCampus" aria-label="选择院区">
+        <option v-for="campus in appStore.campuses" :key="campus" :value="campus">
+          {{ campus }}
+        </option>
       </select>
     </label>
     <span class="environment-badge">{{ appStore.environment }}</span>