feat(ui): extract entity forms into dedicated edit views

Move entity creation and editing from AdminView to separate pages.
Simplify AdminView to focus on system configuration and record deletion.
Add action buttons to list/detail views and protect routes via meta tags.

frontend/src/views/HabitatList.vue

@@ -21,6 +21,9 @@ onMounted(async () => {
   <section class="page-stack">
     <PageHeader title="栖息地" subtitle="查看配方和可能出现的宝可梦。">
       <template #kicker>Habitats</template>
+      <template #actions>
+        <RouterLink class="ui-button ui-button--primary ui-button--small" to="/habitats/new">新增</RouterLink>
+      </template>
     </PageHeader>
 
     <div v-if="loading" class="entity-grid" aria-busy="true" aria-label="正在加载栖息地列表">