chore(deps): align frontend toolchain on vite 7 and split admin bundle

Upgrade admin-web and desktop-client onto Vite 7 / Vitest 4 with the
matching @vitejs/plugin-vue 6 and electron-vite 5, and introduce
manualChunks plus gzip/brotli compression so the admin bundle ships
in smaller, route-aware pieces. ANALYZE=true emits a treemap via
rollup-plugin-visualizer; the generated stats.html is gitignored.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/package.json

@@ -33,15 +33,15 @@
     "@playwright/test": "^1.0.0",
     "@types/node": "^24.0.0",
     "@types/ws": "^8.18.1",
-    "@vitejs/plugin-vue": "^5.2.4",
+    "@vitejs/plugin-vue": "^6.0.6",
     "ant-design-vue": "^4.2.6",
     "electron": "41.2.0",
     "electron-builder": "^25.0.0",
-    "electron-vite": "^2.0.0",
+    "electron-vite": "^5.0.0",
     "typescript": "^5.9.3",
     "unplugin-vue-components": "^32.0.0",
-    "vite": "^5.4.19",
-    "vitest": "^2.0.0",
+    "vite": "^7.3.2",
+    "vitest": "^4.1.5",
     "vue": "^3.5.31",
     "vue-router": "^4.5.1",
     "vue-tsc": "^3.2.6"