chore(frontend): introduce prettier + eslint and prune unused code

- Add Prettier 3 with prettier-plugin-organize-imports (sorts/removes unused imports)
- Add ESLint 10 flat config with typescript-eslint + eslint-plugin-vue + eslint-config-prettier
- Add root scripts: format, format:check, lint, lint:fix
- Reformat 257 files across admin-web, ops-web, desktop-client, packages
- Remove unused locals/exports flagged by --noUnusedLocals/--noUnusedParameters
- Fix duplicate localTabLabel key, surrogate-pair regex u-flag, NBSP literal in regex
- Skip server/ (Go) and apps/browser-extension/ (deprecated per ADR)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/styles.css

@@ -1,8 +1,8 @@
 /* Clean Enterprise UI Reset */
-@import url("https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Noto+Sans+SC:wght@400;500;700&display=swap");
+@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Noto+Sans+SC:wght@400;500;700&display=swap');
 
 :root {
-  font-family: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
+  font-family: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
   color: #141414;
   background-color: #f0f2f5;
   font-synthesis: none;
@@ -19,7 +19,9 @@
   box-sizing: border-box;
 }
 
-html, body, #app {
+html,
+body,
+#app {
   min-height: 100vh;
   margin: 0;
   padding: 0;
@@ -105,7 +107,9 @@ html, body, #app {
 .action-btn.ant-btn {
   color: #8c8c8c;
   font-size: 14px;
-  transition: color 0.2s, background-color 0.2s;
+  transition:
+    color 0.2s,
+    background-color 0.2s;
 }
 
 .action-edit.ant-btn:hover:not(:disabled) {
@@ -139,11 +143,11 @@ html, body, #app {
 }
 
 .ant-layout-header {
-  box-shadow: 0 1px 4px rgba(0,21,41,0.08); /* slight shadow for topbar */
+  box-shadow: 0 1px 4px rgba(0, 21, 41, 0.08); /* slight shadow for topbar */
 }
 
 .ant-card {
-  box-shadow: 0 1px 2px 0 rgba(0,0,0,0.03);
+  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
 }
 
 .ant-menu-dark .ant-menu-item-selected {
@@ -216,7 +220,7 @@ html, body, #app {
   flex-direction: column;
   justify-content: center;
   padding: 60px 48px;
-  box-shadow: -4px 0 16px rgba(0,0,0,0.05);
+  box-shadow: -4px 0 16px rgba(0, 0, 0, 0.05);
 }
 
 .login-header {
@@ -248,7 +252,8 @@ html, body, #app {
     width: 100%;
     align-items: center;
   }
-  .login-header, .ant-form {
+  .login-header,
+  .ant-form {
     width: 100%;
     max-width: 400px;
   }