fix: 管理配方tab所有人可见，未登录时显示登录引导

撤回之前的editor-only限制，改为tab可见但页面内容需登录。

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/views/RecipeManager.vue

@@ -1,5 +1,11 @@
 <template>
   <div class="recipe-manager">
+    <!-- Login prompt for non-logged-in users -->
+    <div v-if="!auth.isLoggedIn" class="login-prompt">
+      <p>登录后可管理配方、创建个人配方集</p>
+      <button class="btn-primary" @click="ui.openLogin()">登录 / 注册</button>
+    </div>
+    <template v-else>
     <!-- Review Bar (admin + senior_editor with assigned reviews) -->
     <div v-if="(auth.isAdmin || auth.canManage) && pendingCount > 0" class="review-bar" @click="showPending = !showPending" >
       📝 待审核配方: {{ pendingCount }} 条
@@ -388,6 +394,7 @@
       @save="onTagPickerSave"
       @close="showTagPicker = false"
     />
+    </template>
   </div>
 </template>
 
@@ -1672,6 +1679,11 @@ watch(() => recipeStore.recipes, () => {
   padding: 0 12px 24px;
 }
 
+.login-prompt {
+  text-align: center; padding: 60px 20px; color: #6b6375;
+}
+.login-prompt p { margin-bottom: 16px; font-size: 15px; }
+
 .review-bar {
   background: linear-gradient(135deg, #fff3e0, #ffe0b2);
   padding: 12px 16px;