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/InstantGenerateModal.vue

@@ -1,19 +1,15 @@
 <script setup lang="ts">
-import GenerateTaskDrawer from "@/components/GenerateTaskDrawer.vue";
+import GenerateTaskDrawer from '@/components/GenerateTaskDrawer.vue'
 
 defineProps<{
-  open: boolean;
-}>();
+  open: boolean
+}>()
 
 const emit = defineEmits<{
-  "update:open": [value: boolean];
-}>();
+  'update:open': [value: boolean]
+}>()
 </script>
 
 <template>
-  <GenerateTaskDrawer
-    :open="open"
-    mode="instant"
-    @update:open="emit('update:open', $event)"
-  />
+  <GenerateTaskDrawer :open="open" mode="instant" @update:open="emit('update:open', $event)" />
 </template>