refactor(desktop): 替换 WebUI 为 Electron + electron-vite 桌面壳方案

- 使用 electron-vite 构建 main/preload，electron-builder 打包分发
- main process: dev 模式直连 localhost:3000，生产模式 spawn sidecar binary
- 添加 loading 页面，server 就绪前显示加载动画
- 更新 catalog 依赖: electron, electron-vite, electron-builder
- 移除 @webui-dev/bun-webui 依赖

apps/desktop/electron-builder.yml

@@ -0,0 +1,38 @@
+appId: com.furtherverse.app
+productName: Furtherverse
+directories:
+  buildResources: build
+files:
+  - '!**/.vscode/*'
+  - '!src/*'
+  - '!electron.vite.config.{js,ts,mjs,cjs}'
+  - '!{.env,.env.*,bun.lock}'
+  - '!{tsconfig.json,tsconfig.node.json}'
+  - '!{AGENTS.md,README.md,CHANGELOG.md}'
+extraResources:
+  - from: resources/
+    to: .
+    filter:
+      - '**/*'
+asarUnpack:
+  - resources/**
+win:
+  executableName: Furtherverse
+nsis:
+  artifactName: ${name}-${version}-setup.${ext}
+  shortcutName: ${productName}
+  uninstallDisplayName: ${productName}
+  createDesktopShortcut: always
+mac:
+  category: public.app-category.productivity
+dmg:
+  artifactName: ${name}-${version}.${ext}
+linux:
+  target:
+    - AppImage
+    - deb
+  maintainer: furtherverse.com
+  category: Utility
+appImage:
+  artifactName: ${name}-${version}.${ext}
+npmRebuild: false