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>

packages/ui-shared/src/tokens/index.ts

@@ -1,13 +1,13 @@
 export const themeTokens = {
-  colorBgPrimary: "var(--geo-color-bg-primary)",
-  colorBgSecondary: "var(--geo-color-bg-secondary)",
-  colorTextPrimary: "var(--geo-color-text-primary)",
-  colorTextSecondary: "var(--geo-color-text-secondary)",
-  colorBorder: "var(--geo-color-border)",
-  colorBrand: "var(--geo-color-brand)",
-  colorSuccess: "var(--geo-color-success)",
-  colorWarn: "var(--geo-color-warn)",
-  colorDanger: "var(--geo-color-danger)",
-} as const;
+  colorBgPrimary: 'var(--geo-color-bg-primary)',
+  colorBgSecondary: 'var(--geo-color-bg-secondary)',
+  colorTextPrimary: 'var(--geo-color-text-primary)',
+  colorTextSecondary: 'var(--geo-color-text-secondary)',
+  colorBorder: 'var(--geo-color-border)',
+  colorBrand: 'var(--geo-color-brand)',
+  colorSuccess: 'var(--geo-color-success)',
+  colorWarn: 'var(--geo-color-warn)',
+  colorDanger: 'var(--geo-color-danger)',
+} as const
 
-export type ThemeTokenKey = keyof typeof themeTokens;
+export type ThemeTokenKey = keyof typeof themeTokens