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/AGENTS.md

@@ -1,27 +1,32 @@
 # AGENTS.md - Desktop App Guidelines
 
-Thin WebUI shell hosting the fullstack server app.
+Thin Electron shell hosting the fullstack server app.
 
 ## Tech Stack
 
-> **⚠️ This project uses Bun — NOT Node.js / npm. All commands use `bun`. Never use `npm`, `npx`, or `node`.**
+> **⚠️ This project uses Bun as the package manager. Runtime is Electron (Node.js). Never use `npm`, `npx`, `yarn`, or `pnpm`.**
 
-- **Type**: WebUI desktop shell
+- **Type**: Electron desktop shell
 - **Design**: Server-driven desktop (thin native window hosting web app)
-- **Runtime**: Bun (Main process) + System browser / WebView (via WebUI)
-- **Window Library**: [webui-dev/webui](https://github.com/webui-dev/webui) — opens installed browser or native WebView as GUI
-- **Build**: Turborepo
+- **Runtime**: Electron (Main/Renderer) + Sidecar server binary (Bun-compiled)
+- **Build Tool**: electron-vite (Vite-based, handles main + preload builds)
+- **Packager**: electron-builder (installers, signing, auto-update)
+- **Orchestration**: Turborepo
 
 ## Architecture
 
-- **Server-driven design**: The desktop app is a "thin" native shell. It does not contain UI or business logic; it opens a browser window pointing to the `apps/server` TanStack Start application.
-- **Dev mode**: Waits for the Vite dev server at `localhost:3000`, then opens a WebUI window. Requires `apps/server` to be running separately.
-- **WebUI**: Uses `@webui-dev/bun-webui` (FFI-based C library binding). Auto-detects and opens the best available browser in a private profile, or uses the system WebView.
+- **Server-driven design**: The desktop app is a "thin" native shell. It does not contain UI or business logic; it opens a BrowserWindow pointing to the `apps/server` TanStack Start application.
+- **Dev mode**: Opens a BrowserWindow pointing to `localhost:3000`. Requires `apps/server` to be running separately (Turbo handles this).
+- **Production mode**: Spawns a compiled server binary (from `resources/`) as a sidecar process, waits for readiness, then loads its URL.
 
 ## Commands
 
 ```bash
-bun dev                    # Open WebUI window (requires server dev running)
+bun dev                    # electron-vite dev (requires server dev running)
+bun build                  # electron-vite build (main + preload)
+bun build:win              # Build + package for Windows
+bun build:mac              # Build + package for macOS
+bun build:linux            # Build + package for Linux
 bun fix                    # Biome auto-fix
 bun typecheck              # TypeScript check
 ```
@@ -31,27 +36,40 @@ bun typecheck              # TypeScript check
 ```
 .
 ├── src/
-│   └── bun/
-│       └── index.ts       # Main process entry (server readiness check + WebUI window)
-├── package.json           # Scripts and dependencies
-├── turbo.json             # Dev pipeline (depends on server dev)
-└── AGENTS.md              # Desktop guidelines (this file)
+│   ├── main/
+│   │   └── index.ts       # Main process (server lifecycle + BrowserWindow)
+│   └── preload/
+│       └── index.ts       # Preload script (security isolation)
+├── resources/             # Sidecar binaries (gitignored, copied from server build)
+├── out/                   # electron-vite build output (gitignored)
+├── electron.vite.config.ts
+├── electron-builder.yml   # Packaging configuration
+├── package.json
+├── turbo.json
+└── AGENTS.md
 ```
 
 ## Development Workflow
 
-1. **Start server**: In `apps/server`, run `bun dev`.
-2. **Start desktop**: In `apps/desktop`, run `bun dev`.
-3. **Connection**: The desktop app polls `localhost:3000` until responsive, then opens the browser window.
+1. **Start server**: `bun dev` in `apps/server` (or use root `bun dev` via Turbo).
+2. **Start desktop**: `bun dev` in `apps/desktop`.
+3. **Connection**: Main process polls `localhost:3000` until responsive, then opens BrowserWindow.
+
+## Production Build Workflow
+
+1. **Build server**: `bun build` in `apps/server` → `.output/`
+2. **Compile server**: `bun compile` in `apps/server` → `out/server-{platform}`
+3. **Copy binary**: Copy the platform-appropriate binary to `apps/desktop/resources/server`
+4. **Package desktop**: `bun build:linux` (or `:mac` / `:win`) in `apps/desktop`
 
 ## Critical Rules
 
 **DO:**
 - Use arrow functions for all utility functions.
-- Ensure `apps/server` dev server is running before starting desktop.
+- Keep the desktop app as a thin shell — no UI or business logic.
 - Use `catalog:` for all dependency versions in `package.json`.
 
 **DON'T:**
-- Use `npm`, `npx`, `node`, `yarn`, or `pnpm`. Always use `bun`.
-- Include UI components or business logic in the desktop app (keep it thin).
+- Use `npm`, `npx`, `yarn`, or `pnpm`. Use `bun` for package management.
+- Include UI components or business logic in the desktop app.
 - Use `as any` or `@ts-ignore`.