feat: 购油方案 — 会员请求+老师定制+购油清单

后端:
- oil_plans/oil_plan_recipes 表
- 7个API: teachers列表、方案CRUD、配方增删、购油清单计算
- 购油清单自动算月消耗、瓶数、费用，交叉比对库存

前端:
- 会员端(库存页): 请求方案→选老师→描述需求；查看购油清单
- 老师端(用户管理): 接收请求→选配方+频率→激活方案
- plans store 管理状态

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

frontend/src/views/Inventory.vue

@@ -1,5 +1,78 @@
 <template>
   <div class="inventory-page">
+    <!-- My Oil Plan -->
+    <template v-if="auth.isLoggedIn">
+      <!-- Active plan: show shopping list -->
+      <div v-if="plansStore.activePlan" class="plan-section">
+        <div class="plan-header">
+          <span class="plan-title">📋 {{ plansStore.activePlan.title || '我的购油方案' }}</span>
+          <span class="plan-teacher">by {{ plansStore.activePlan.teacher_name || '老师' }}</span>
+        </div>
+        <div class="plan-recipes-summary">
+          <span v-for="r in plansStore.activePlan.recipes" :key="r.id" class="plan-recipe-chip">
+            {{ r.recipe_name }} × {{ r.times_per_month }}/月
+          </span>
+        </div>
+        <div v-if="plansStore.shoppingList.length" class="shopping-list">
+          <div class="shopping-header">🛒 本月购油清单</div>
+          <div class="shopping-total">
+            预计月消费：¥{{ shoppingTotal }}
+          </div>
+          <div v-for="item in plansStore.shoppingList" :key="item.oil_name"
+            class="shopping-item" :class="{ owned: item.in_inventory }">
+            <span class="shop-name">{{ item.oil_name }}</span>
+            <span class="shop-drops">{{ item.monthly_drops }}滴/月</span>
+            <span class="shop-bottles">{{ item.bottles_needed }}瓶</span>
+            <span class="shop-cost">¥{{ item.total_cost }}</span>
+            <button v-if="!item.in_inventory" class="shop-add-btn" @click="addOilFromPlan(item.oil_name)">
+              加入库存
+            </button>
+            <span v-else class="shop-owned-tag">已有</span>
+          </div>
+        </div>
+      </div>
+
+      <!-- Pending plan -->
+      <div v-else-if="plansStore.pendingPlans.length" class="plan-section plan-pending">
+        <div class="plan-header">
+          <span class="plan-title">⏳ 方案审核中</span>
+        </div>
+        <p class="plan-desc">{{ plansStore.pendingPlans[0].health_desc }}</p>
+      </div>
+
+      <!-- No plan: request button -->
+      <div v-else class="plan-request-bar">
+        <button class="btn-primary" @click="showPlanRequest = true">📋 请求定制购油方案</button>
+      </div>
+
+      <!-- Plan request modal -->
+      <div v-if="showPlanRequest" class="overlay" @mousedown.self="showPlanRequest = false">
+        <div class="overlay-panel" style="max-width:400px">
+          <div class="overlay-header">
+            <h3>请求定制方案</h3>
+            <button class="btn-close" @click="showPlanRequest = false">✕</button>
+          </div>
+          <div style="padding:16px">
+            <label class="form-label">描述你的健康需求</label>
+            <textarea v-model="planHealthDesc" class="form-textarea" rows="4"
+              placeholder="例如：家里有老人膝盖痛，小孩经常感冒咳嗽，我自己想改善睡眠..."></textarea>
+            <label class="form-label" style="margin-top:12px">选择老师</label>
+            <select v-model="planTeacherId" class="form-select">
+              <option value="">请选择</option>
+              <option v-for="t in plansStore.teachers" :key="t.id" :value="t.id">
+                {{ t.display_name }}
+              </option>
+            </select>
+            <button class="btn-primary" style="width:100%;margin-top:16px"
+              :disabled="!planHealthDesc.trim() || !planTeacherId"
+              @click="submitPlanRequest">
+              发送请求
+            </button>
+          </div>
+        </div>
+      </div>
+    </template>
+
     <!-- Search + direct add -->
     <div class="search-box">
       <input
@@ -93,12 +166,14 @@ import { useAuthStore } from '../stores/auth'
 import { useOilsStore } from '../stores/oils'
 import { useRecipesStore } from '../stores/recipes'
 import { useUiStore } from '../stores/ui'
+import { usePlansStore } from '../stores/plans'
 import { api } from '../composables/useApi'
 
 const auth = useAuthStore()
 const oils = useOilsStore()
 const recipeStore = useRecipesStore()
 const ui = useUiStore()
+const plansStore = usePlansStore()
 
 const searchQuery = ref('')
 const ownedOils = ref([])
@@ -233,14 +308,54 @@ async function toggleOil(name) {
   await saveInventory()
 }
 
+// Plan request
+const showPlanRequest = ref(false)
+const planHealthDesc = ref('')
+const planTeacherId = ref('')
+
+const shoppingTotal = computed(() =>
+  plansStore.shoppingList.filter(i => !i.in_inventory).reduce((s, i) => s + i.total_cost, 0).toFixed(2)
+)
+
+async function submitPlanRequest() {
+  try {
+    await plansStore.createPlan(planHealthDesc.value, planTeacherId.value)
+    showPlanRequest.value = false
+    planHealthDesc.value = ''
+    planTeacherId.value = ''
+    ui.showToast('已发送方案请求')
+  } catch {
+    ui.showToast('发送失败')
+  }
+}
+
+async function addOilFromPlan(name) {
+  if (!ownedOils.value.includes(name)) {
+    ownedOils.value.push(name)
+    ownedOils.value.sort((a, b) => a.localeCompare(b, 'zh'))
+    await saveInventory()
+  }
+  // Refresh shopping list
+  if (plansStore.activePlan) {
+    await plansStore.loadShoppingList(plansStore.activePlan.id)
+  }
+  ui.showToast(`${name} 已加入库存`)
+}
+
 async function clearAll() {
   ownedOils.value = []
   await saveInventory()
   ui.showToast('已清空库存')
 }
 
-onMounted(() => {
-  loadInventory()
+onMounted(async () => {
+  await loadInventory()
+  if (auth.isLoggedIn) {
+    await Promise.all([plansStore.loadPlans(), plansStore.loadTeachers()])
+    if (plansStore.activePlan) {
+      await plansStore.loadShoppingList(plansStore.activePlan.id)
+    }
+  }
 })
 </script>
 
@@ -473,4 +588,46 @@ onMounted(() => {
   font-size: 13px;
   padding: 24px 0;
 }
+
+/* Plan section */
+.plan-section {
+  background: #f8faf8; border: 1.5px solid #d4e8d4; border-radius: 12px;
+  padding: 14px; margin-bottom: 16px;
+}
+.plan-pending { border-color: #e5e4e7; background: #fafafa; }
+.plan-header { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
+.plan-title { font-weight: 600; font-size: 15px; color: #2e7d5a; }
+.plan-teacher { font-size: 12px; color: #b0aab5; }
+.plan-desc { font-size: 13px; color: #6b6375; margin: 0; }
+.plan-recipes-summary { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 10px; }
+.plan-recipe-chip {
+  font-size: 11px; padding: 3px 10px; border-radius: 8px;
+  background: #e8f5e9; color: #2e7d5a; white-space: nowrap;
+}
+.shopping-list { margin-top: 8px; }
+.shopping-header { font-weight: 600; font-size: 14px; color: #3e3a44; margin-bottom: 4px; }
+.shopping-total { font-size: 12px; color: #5a7d5e; margin-bottom: 8px; font-weight: 500; }
+.shopping-item {
+  display: flex; align-items: center; gap: 8px; padding: 6px 0;
+  border-bottom: 1px solid #eee; font-size: 13px;
+}
+.shopping-item.owned { opacity: 0.5; }
+.shop-name { flex: 1; font-weight: 500; color: #3e3a44; }
+.shop-drops { color: #6b6375; font-size: 12px; white-space: nowrap; }
+.shop-bottles { color: #5a7d5e; font-size: 12px; white-space: nowrap; }
+.shop-cost { color: #5a7d5e; font-weight: 600; font-size: 12px; white-space: nowrap; }
+.shop-add-btn {
+  padding: 2px 10px; border-radius: 6px; border: 1px solid #7ec6a4;
+  background: #fff; color: #2e7d5a; font-size: 11px; cursor: pointer; font-family: inherit;
+}
+.shop-add-btn:hover { background: #e8f5e9; }
+.shop-owned-tag { font-size: 11px; color: #b0aab5; }
+.plan-request-bar { text-align: center; margin-bottom: 16px; }
+.overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.4); z-index: 100; display: flex; align-items: center; justify-content: center; }
+.overlay-panel { background: #fff; border-radius: 14px; width: 90%; max-width: 420px; max-height: 80vh; overflow-y: auto; }
+.overlay-header { display: flex; align-items: center; justify-content: space-between; padding: 14px 16px; border-bottom: 1px solid #eee; }
+.overlay-header h3 { margin: 0; font-size: 16px; }
+.form-label { display: block; font-size: 13px; color: #6b6375; margin-bottom: 4px; font-weight: 500; }
+.form-textarea { width: 100%; border: 1.5px solid #e5e4e7; border-radius: 8px; padding: 8px; font-size: 13px; font-family: inherit; resize: vertical; box-sizing: border-box; }
+.form-select { width: 100%; border: 1.5px solid #e5e4e7; border-radius: 8px; padding: 8px; font-size: 13px; font-family: inherit; box-sizing: border-box; }
 </style>