feat(shop): add product taxonomy write REST for editor

Expose POST /shop/products/taxonomy to create category/tag terms,
enrich GET term payload with slug/parent/count, and let
ProductEditorDrawer create categories and ensure tags without WP
native UI.

assets/admin/src/pages/shop/components/ProductEditorDrawer.vue

@@ -45,14 +45,26 @@
         <n-divider title-placement="left">分类与标签</n-divider>
 
         <n-form-item label="分类">
-          <n-select
-            v-model:value="form.categories"
-            :options="categoryOptions"
-            multiple
-            filterable
-            placeholder="选择分类（可多选）"
-            :loading="loadingTaxonomy"
-          />
+          <n-space vertical style="width:100%;">
+            <n-select
+              v-model:value="form.categories"
+              :options="categoryOptions"
+              multiple
+              filterable
+              placeholder="选择分类（可多选）"
+              :loading="loadingTaxonomy"
+              style="width:100%;"
+            />
+            <n-space>
+              <n-input
+                v-model:value="newCategoryName"
+                placeholder="新建分类名称"
+                style="min-width:180px;"
+                @keyup.enter="createCategory"
+              />
+              <n-button :loading="creatingCategory" @click="createCategory">新建分类</n-button>
+            </n-space>
+          </n-space>
         </n-form-item>
 
         <n-form-item label="标签">
@@ -62,8 +74,9 @@
             multiple
             filterable
             tag
-            placeholder="输入标签后回车"
+            placeholder="选择或输入新标签后回车"
             :loading="loadingTaxonomy"
+            @update:value="onTagsUpdate"
           />
         </n-form-item>
 
@@ -164,6 +177,9 @@ const shippingModeOptions = [
 
 const categoryOptions = ref([])
 const tagOptions = ref([])
+const newCategoryName = ref('')
+const creatingCategory = ref(false)
+const creatingTagNames = new Set()
 
 // Load taxonomy options
 async function loadTaxonomy() {
@@ -175,12 +191,75 @@ async function loadTaxonomy() {
       tagOptions.value = (res.data.tags || []).map(t => ({ label: t.name, value: t.name }))
     }
   } catch {
-    // Taxonomy endpoint may not exist yet — silent fallback
+    message.warning('分类标签加载失败，可稍后重试')
   } finally {
     loadingTaxonomy.value = false
   }
 }
 
+async function createCategory() {
+  const name = (newCategoryName.value || '').trim()
+  if (!name) {
+    message.warning('请输入分类名称')
+    return
+  }
+  creatingCategory.value = true
+  try {
+    const res = await api.request('/shop/products/taxonomy', {
+      method: 'POST',
+      data: { taxonomy: 'category', name },
+    })
+    const term = res?.data
+    if (term?.id) {
+      if (!categoryOptions.value.some(o => o.value === term.id)) {
+        categoryOptions.value = [...categoryOptions.value, { label: term.name, value: term.id }]
+      }
+      if (!form.categories.includes(term.id)) {
+        form.categories = [...form.categories, term.id]
+      }
+      newCategoryName.value = ''
+      message.success(term.existing ? '分类已存在，已选中' : '分类已创建')
+    }
+  } catch (err) {
+    message.error(err?.message || '创建分类失败')
+  } finally {
+    creatingCategory.value = false
+  }
+}
+
+async function ensureTagTerm(name) {
+  const label = String(name || '').trim()
+  if (!label || creatingTagNames.has(label)) return
+  const exists = tagOptions.value.some(o => o.value === label || o.label === label)
+  if (exists) return
+
+  creatingTagNames.add(label)
+  try {
+    const res = await api.request('/shop/products/taxonomy', {
+      method: 'POST',
+      data: { taxonomy: 'tag', name: label },
+    })
+    const term = res?.data
+    if (term?.name && !tagOptions.value.some(o => o.value === term.name)) {
+      tagOptions.value = [...tagOptions.value, { label: term.name, value: term.name }]
+    }
+  } catch {
+    // Keep typed tag in form; backend product save still accepts string tags.
+  } finally {
+    creatingTagNames.delete(label)
+  }
+}
+
+function onTagsUpdate(values) {
+  const list = Array.isArray(values) ? values : []
+  form.tags = list
+  list.forEach((name) => {
+    if (!tagOptions.value.some(o => o.value === name)) {
+      ensureTagTerm(name)
+    }
+  })
+}
+
 // Load product data when editing
 watch(() => props.show, async (val) => {
   if (val) {