feat: 数据概览/操作日志/批量操作 + 首页合格档案数

后台新增「数据概览」(商品/合格/按状态/品牌/分类/待审核) 与「操作日志」(全局审计分页)；商品列表支持多选批量改状态/分类。公开首页标题改为「天工」并展示合格档案数；新增公开接口 /api/v1/stats 与后台 /api/stats、/api/audit、/api/products/bulk。合格口径=quality_score≥0.6 且在用。

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

admin-frontend/src/App.tsx

@@ -7,9 +7,18 @@ import SubmissionsPage from "./components/SubmissionsPage";
 import ApiKeysPage from "./components/ApiKeysPage";
 import CategoriesPage from "./components/CategoriesPage";
 import BrandsPage from "./components/BrandsPage";
-import { FolderTree, Inbox, KeyRound, LogOut, Package, Tag } from "lucide-react";
+import StatsPage from "./components/StatsPage";
+import AuditLogPage from "./components/AuditLogPage";
+import { BarChart3, FolderTree, Inbox, KeyRound, LogOut, Package, ScrollText, Tag } from "lucide-react";
 
-type Tab = "products" | "submissions" | "categories" | "brands" | "keys";
+type Tab =
+  | "overview"
+  | "products"
+  | "submissions"
+  | "categories"
+  | "brands"
+  | "audit"
+  | "keys";
 type View = { name: "list" } | { name: "detail"; id: string };
 
 export default function App() {
@@ -74,6 +83,16 @@ export default function App() {
             天工商品档案公共仓 · 后台
           </div>
           <nav className="flex items-center gap-1 text-sm">
+            <button
+              onClick={() => setTab("overview")}
+              className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
+                tab === "overview"
+                  ? "bg-emerald-50 text-emerald-700"
+                  : "text-gray-600 hover:bg-gray-100"
+              }`}
+            >
+              <BarChart3 className="h-4 w-4" /> 数据概览
+            </button>
             <button
               onClick={() => {
                 setTab("products");
@@ -125,6 +144,16 @@ export default function App() {
             >
               <Tag className="h-4 w-4" /> 品牌管理
             </button>
+            <button
+              onClick={() => setTab("audit")}
+              className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
+                tab === "audit"
+                  ? "bg-emerald-50 text-emerald-700"
+                  : "text-gray-600 hover:bg-gray-100"
+              }`}
+            >
+              <ScrollText className="h-4 w-4" /> 操作日志
+            </button>
             <button
               onClick={() => setTab("keys")}
               className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
@@ -148,7 +177,11 @@ export default function App() {
         </div>
       </header>
       <main className="flex-1 overflow-auto p-6">
-        {tab === "keys" ? (
+        {tab === "overview" ? (
+          <StatsPage />
+        ) : tab === "audit" ? (
+          <AuditLogPage />
+        ) : tab === "keys" ? (
           <ApiKeysPage />
         ) : tab === "categories" ? (
           <CategoriesPage />