refactor(seller): 列表页抽离 useTable 重构与通用 UI 规范优化

- 抽离通用 useTable composable，并迁移 13 个典型列表页（采购/报损/订单/售后/统计/营销等）
- 增加表格与树组件全局空状态 (el-empty) 样式规范
- 补齐视图图片语义化 alt，并添加全局图片加载异常 SVG 占位兜底
- 替换遗留的 $Message 兼容语法为 ElMessage
- 将 WAP 店铺装修模板的 Options API 统一为 defineOptions
- 优化数据报表卡片视觉样式，并移除失效的品牌筛选选项
- 清理冗余依赖 vuex，将 sass-loader 调整至 devDependencies

seller/src/main.js

@@ -5,6 +5,7 @@ import App from "./App.vue";
 import { router } from "./router/index";
 import { setupElementPlus } from "@/plugins/element";
 import { setupLegacyMessage } from "@/utils/message";
+import { setupImgFallback } from "@/utils/imgFallback";
 import liliDialog from "@/views/lili-dialog";
 import PriceColorScheme from "@/components/price-color-scheme.vue";
 import { install as installVueQr } from "vue-qr";
@@ -39,6 +40,7 @@ const app = createApp(App);
 
 setupElementPlus(app);
 setupLegacyMessage(app);
+setupImgFallback();
 installVueQr(app);
 
 app.use(router);