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/desktop-client/src/main/adapters/media-image.test.ts

@@ -1,8 +1,8 @@
-import { Buffer } from "node:buffer";
+import { Buffer } from 'node:buffer'
 
-import { describe, expect, it, vi } from "vitest";
+import { describe, expect, it, vi } from 'vitest'
 
-vi.mock("electron", () => ({
+vi.mock('electron', () => ({
   nativeImage: {
     createFromBuffer: () => ({
       isEmpty: () => false,
@@ -15,33 +15,30 @@ vi.mock("electron", () => ({
       toPNG: () => Buffer.from([]),
     }),
   },
-}));
+}))
 
-vi.mock("../transport/api-client", () => ({
+vi.mock('../transport/api-client', () => ({
   fetchDesktopApiURL: vi.fn(),
   resolveDesktopApiURL: (path: string) => `http://127.0.0.1:8080${path}`,
-}));
+}))
 
-import {
-  buildAssetURLCandidates,
-  getCenteredCropRect,
-} from "./media-image";
+import { buildAssetURLCandidates, getCenteredCropRect } from './media-image'
 
-describe("media image helpers", () => {
-  it("resolves public asset URLs through public and authenticated desktop candidates", () => {
-    expect(buildAssetURLCandidates("/api/public/assets/12")).toEqual([
-      "http://127.0.0.1:8080/api/public/assets/12?format=png",
-      "http://127.0.0.1:8080/api/desktop/content/assets/12?format=png",
-      "http://127.0.0.1:8080/api/public/assets/12",
-    ]);
-  });
+describe('media image helpers', () => {
+  it('resolves public asset URLs through public and authenticated desktop candidates', () => {
+    expect(buildAssetURLCandidates('/api/public/assets/12')).toEqual([
+      'http://127.0.0.1:8080/api/public/assets/12?format=png',
+      'http://127.0.0.1:8080/api/desktop/content/assets/12?format=png',
+      'http://127.0.0.1:8080/api/public/assets/12',
+    ])
+  })
 
-  it("centers crop rectangles at the requested ratio", () => {
-    const rect = getCenteredCropRect(1600, 1000, 4 / 3);
+  it('centers crop rectangles at the requested ratio', () => {
+    const rect = getCenteredCropRect(1600, 1000, 4 / 3)
 
-    expect(rect.x).toBeCloseTo(133.333, 3);
-    expect(rect.y).toBeCloseTo(0);
-    expect(rect.width).toBeCloseTo(1333.333, 3);
-    expect(rect.height).toBeCloseTo(1000);
-  });
-});
+    expect(rect.x).toBeCloseTo(133.333, 3)
+    expect(rect.y).toBeCloseTo(0)
+    expect(rect.width).toBeCloseTo(1333.333, 3)
+    expect(rect.height).toBeCloseTo(1000)
+  })
+})