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/components/kol/KolVariablePanel.vue

@@ -1,27 +1,27 @@
 <script setup lang="ts">
 import {
-  FontSizeOutlined,
-  EditOutlined,
-  OrderedListOutlined,
-  NumberOutlined,
   CheckSquareOutlined,
-} from "@ant-design/icons-vue";
-import { useI18n } from "vue-i18n";
+  EditOutlined,
+  FontSizeOutlined,
+  NumberOutlined,
+  OrderedListOutlined,
+} from '@ant-design/icons-vue'
+import { useI18n } from 'vue-i18n'
 
-const { t } = useI18n();
+const { t } = useI18n()
 
 const componentTypes = [
-  { type: "input", icon: FontSizeOutlined },
-  { type: "textarea", icon: EditOutlined },
-  { type: "select", icon: OrderedListOutlined },
-  { type: "number", icon: NumberOutlined },
-  { type: "checkbox", icon: CheckSquareOutlined },
-] as const;
+  { type: 'input', icon: FontSizeOutlined },
+  { type: 'textarea', icon: EditOutlined },
+  { type: 'select', icon: OrderedListOutlined },
+  { type: 'number', icon: NumberOutlined },
+  { type: 'checkbox', icon: CheckSquareOutlined },
+] as const
 
 function onDragStart(event: DragEvent, type: string) {
   if (event.dataTransfer) {
-    event.dataTransfer.setData("application/kol-variable-type", type);
-    event.dataTransfer.effectAllowed = "copy";
+    event.dataTransfer.setData('application/kol-variable-type', type)
+    event.dataTransfer.effectAllowed = 'copy'
   }
 }
 </script>