feat(admin): 分类管理（分类树增删改移 + 后台页面）

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

admin-frontend/src/App.tsx

@@ -5,9 +5,10 @@ import ProductList from "./components/ProductList";
 import ProductDetail from "./components/ProductDetail";
 import SubmissionsPage from "./components/SubmissionsPage";
 import ApiKeysPage from "./components/ApiKeysPage";
-import { Inbox, KeyRound, LogOut, Package } from "lucide-react";
+import CategoriesPage from "./components/CategoriesPage";
+import { FolderTree, Inbox, KeyRound, LogOut, Package } from "lucide-react";
 
-type Tab = "products" | "submissions" | "keys";
+type Tab = "products" | "submissions" | "categories" | "keys";
 type View = { name: "list" } | { name: "detail"; id: string };
 
 export default function App() {
@@ -100,6 +101,19 @@ export default function App() {
                 </span>
               )}
             </button>
+            <button
+              onClick={() => {
+                setTab("categories");
+                setView({ name: "list" });
+              }}
+              className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
+                tab === "categories"
+                  ? "bg-emerald-50 text-emerald-700"
+                  : "text-gray-600 hover:bg-gray-100"
+              }`}
+            >
+              <FolderTree className="h-4 w-4" /> 分类管理
+            </button>
             <button
               onClick={() => setTab("keys")}
               className={`px-3 py-1.5 rounded-md flex items-center gap-1.5 ${
@@ -125,6 +139,8 @@ export default function App() {
       <main className="flex-1 overflow-auto p-6">
         {tab === "keys" ? (
           <ApiKeysPage />
+        ) : tab === "categories" ? (
+          <CategoriesPage />
         ) : tab === "submissions" ? (
           <SubmissionsPage onPending={setPending} />
         ) : view.name === "list" ? (