refactor: 四端完成 Options API → script setup + vuex → pinia 迁移

- buyer(95) / seller(169) / im(53) / manager(280) 共 597 个组件全部从 Options API 转换为 <script setup>
- 四端 vuex 全部移除，状态管理统一迁移至 pinia 4（stores/ 目录）
- util.js 等基础设施去除 vm 首参依赖；全局属性（$Message/$filters 等）在 script 内改为具名导入
- 被外部 ref 访问的公共组件均已补齐 defineExpose（清单见各端 MIGRATION-VUE3.md）
- 各端 eslint 启用 vue/component-api-style 防止新代码回退 Options API
- 四端 yarn build 全部通过；迁移约定与注意事项已更新至各端 MIGRATION-VUE3.md

seller/src/App.vue

@@ -4,33 +4,36 @@
   </div>
 </template>
 
-<script>
+<script setup>
+import { onMounted } from "vue";
 import Cookies from "js-cookie";
 import util from "@/libs/util";
+import { getStore } from "@/libs/storage";
 import { getCategoryTree } from "@/api/goods.js";
+import { useAppStore } from "@/stores/app";
 
-export default {
-  name: "App",
-  mounted() {
-    const loggedIn =
-      this.getStore("accessToken") || Cookies.get("userInfoSeller");
-    if (loggedIn) {
-      util.bootstrapDynamicRoutesFromCache();
-      util.initRouter(this);
-      this.$store.commit("setOpenedList");
-      this.$store.commit("initCachepage");
-      if (!localStorage.getItem("category")) {
-        getCategoryTree()
-          .then((res) => {
-            if (res.success && Array.isArray(res.result)) {
-              localStorage.setItem("category", JSON.stringify(res.result));
-            }
-          })
-          .catch(() => {});
-      }
+defineOptions({ name: "App" });
+
+const appStore = useAppStore();
+
+onMounted(() => {
+  const loggedIn = getStore("accessToken") || Cookies.get("userInfoSeller");
+  if (loggedIn) {
+    util.bootstrapDynamicRoutesFromCache();
+    util.initRouter();
+    appStore.setOpenedList();
+    appStore.initCachepage();
+    if (!localStorage.getItem("category")) {
+      getCategoryTree()
+        .then((res) => {
+          if (res.success && Array.isArray(res.result)) {
+            localStorage.setItem("category", JSON.stringify(res.result));
+          }
+        })
+        .catch(() => {});
     }
-  },
-};
+  }
+});
 </script>
 
 <style>