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/RecipeList.vue

@@ -43,6 +43,9 @@ watch(recipeQuery, loadRecipes);
   <section class="page-stack">
     <PageHeader title="材料单" subtitle="按分类浏览材料单和需要材料。">
       <template #kicker>Recipes</template>
+      <template #actions>
+        <RouterLink class="ui-button ui-button--primary ui-button--small" to="/recipes/new">新增</RouterLink>
+      </template>
     </PageHeader>
 
     <Tabs v-if="options" id="recipe-category" v-model="categoryId" :tabs="categoryTabs" label="分类" />