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/yarn.lock

@@ -2138,7 +2138,7 @@
   optionalDependencies:
     prettier "^1.18.2 || ^2.0.0"
 
-"@vue/devtools-api@^6.0.0-beta.11", "@vue/devtools-api@^6.6.4":
+"@vue/devtools-api@^6.6.4":
   version "6.6.4"
   resolved "https://registry.npmjs.org/@vue/devtools-api/-/devtools-api-6.6.4.tgz#cbe97fe0162b365edc1dba80e173f90492535343"
   integrity sha512-sGhTPMuXqZ1rVOk32RylztWkfXTRhuS7vgAKv0zjqk8gbsHkJ7xfFf+jbySxt7tWObEJwyKaHMikV/WGDiQm8g==
@@ -5238,6 +5238,11 @@ normalize-wheel-es@^1.2.0:
   resolved "https://registry.npmjs.org/normalize-wheel-es/-/normalize-wheel-es-1.2.0.tgz#0fa2593d619f7245a541652619105ab076acf09e"
   integrity sha512-Wj7+EJQ8mSuXr2iWfnujrimU35R2W4FAErEyTmJoJ7ucwTn2hOUSsRehMb5RSYkxXGTM7Y9QpvPmp++w5ftoJw==
 
+nostics@^1.1.4:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/nostics/-/nostics-1.3.0.tgz#e1d538463acb0207f9a0ef9ec551b075930559c4"
+  integrity sha512-wzRsrJwNlFbqIRQt8aCeL2WE8USip/uuvGSOZV1D02CxX8ABTMbw8IywKjH7yWHETMXbWJI4OBpihg9rmz2Vyg==
+
 npm-run-path@^2.0.0:
   version "2.0.2"
   resolved "https://registry.npmjs.org/npm-run-path/-/npm-run-path-2.0.2.tgz"
@@ -5526,6 +5531,13 @@ picomatch@^2.0.4, picomatch@^2.2.1, picomatch@^2.3.1:
   resolved "https://registry.npmjs.org/picomatch/-/picomatch-2.3.1.tgz"
   integrity sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==
 
+pinia@^4.0.3:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/pinia/-/pinia-4.0.3.tgz#9cf9e353b3602e24a96e4ca4425817ecb9993292"
+  integrity sha512-XMQqpvjgG7LMqVhhFUzKLT4KEbsYbfZZ0CZU9PgdFm1O2VKBmIkykL8+SfNhOaT7sR0wT6BEgKT0YNDYWgmVRA==
+  dependencies:
+    nostics "^1.1.4"
+
 pkg-dir@^4.1.0:
   version "4.2.0"
   resolved "https://registry.npmjs.org/pkg-dir/-/pkg-dir-4.2.0.tgz"
@@ -6947,13 +6959,6 @@ vuedraggable@^4.1.0:
   dependencies:
     sortablejs "1.14.0"
 
-vuex@^4.1.0:
-  version "4.1.0"
-  resolved "https://registry.npmjs.org/vuex/-/vuex-4.1.0.tgz#aa1b3ea5c7385812b074c86faeeec2217872e36c"
-  integrity sha512-hmV6UerDrPcgbSy9ORAtNXDr9M4wlNP4pEFKye4ujJF8oqgFFuxDCdOLS3eNoRTtq5O3hoBDh9Doj1bQMYHRbQ==
-  dependencies:
-    "@vue/devtools-api" "^6.0.0-beta.11"
-
 watchpack@^2.4.0, watchpack@^2.5.2:
   version "2.5.2"
   resolved "https://registry.npmjs.org/watchpack/-/watchpack-2.5.2.tgz#e12e82d84674266fc1c6dbfe38891b92ff0522ec"