feat(desktop): Chinese menu, branded icon, and a self-contained harness bundle

Localizes the Electron application menu (文件/编辑/视图/窗口/帮助 plus the
macOS app menu), adds a branded 1024px app icon (window + per-target icns/ico),
and makes the packaged app fully self-contained. Because the harness's pnpm
workspace does not cleanly materialize via pnpm deploy or electron-builder's
dependency resolution (per-package symlinks to vendored sources, native addons,
a separate frontend dist), scripts/build-harness.mjs assembles the repository's
working runtime — node_modules, vendor, packages, native, apps/cli, apps/web,
and a bundled Node binary — into build/harness. electron-builder ships it as an
extraResource at Resources/harness, and the main process spawns that bundled
node + dsh entry when packaged (keeping the system-Node child during dev). Adds
a comprehensive README and ignores the multi-GB harness/dist from git.

Co-Authored-By: Claude <noreply@anthropic.com>

apps/desktop/package.json

@@ -4,6 +4,7 @@
   "version": "0.1.0-rc.5",
   "private": true,
   "type": "module",
+  "author": "PineSound",
   "main": "lib/types/main.js",
   "files": [
     "lib/types/*.js",
@@ -12,6 +13,7 @@
   ],
   "scripts": {
     "build": "tsc -b tsconfig.json",
+    "build:harness": "node scripts/build-harness.mjs",
     "typecheck": "tsc -b tsconfig.json",
     "test": "vitest run",
     "pack": "electron-builder"