feat: 用户管理直接开通/撤销商业认证

- 用户列表每行加💼按钮，未认证点击开通，已认证点击撤销
- 新增 /api/business-grant/{id} 端点
- 开通/撤销时通知用户

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

frontend/src/views/UserManagement.vue

@@ -102,6 +102,8 @@
             <option value="editor">编辑</option>
             <option value="senior_editor">高级编辑</option>
           </select>
+          <button v-if="!u.business_verified" class="btn-sm btn-outline" @click="grantBusiness(u)" title="开通商业认证">💼</button>
+          <button v-else class="btn-sm btn-outline" @click="revokeBusiness(u)" title="撤销商业认证" style="opacity:0.5">💼✕</button>
           <button class="btn-sm btn-delete" @click="removeUser(u)" title="删除用户">🗑️</button>
         </div>
       </div>
@@ -240,6 +242,36 @@ async function removeUser(user) {
   }
 }
 
+async function grantBusiness(user) {
+  const ok = await showConfirm(`直接为「${user.display_name || user.username}」开通商业认证？`)
+  if (!ok) return
+  const id = user._id || user.id
+  try {
+    const res = await api(`/api/business-grant/${id}`, { method: 'POST' })
+    if (res.ok) {
+      user.business_verified = 1
+      ui.showToast('已开通商业认证')
+    }
+  } catch {
+    ui.showToast('操作失败')
+  }
+}
+
+async function revokeBusiness(user) {
+  const ok = await showConfirm(`撤销「${user.display_name || user.username}」的商业认证？`)
+  if (!ok) return
+  const id = user._id || user.id
+  try {
+    const res = await api(`/api/business-revoke/${id}`, { method: 'POST' })
+    if (res.ok) {
+      user.business_verified = 0
+      ui.showToast('已撤销商业认证')
+    }
+  } catch {
+    ui.showToast('操作失败')
+  }
+}
+
 async function approveTranslation(t) {
   const id = t._id || t.id
   try {