chore: 版本号 0.1.0 → 0.9.0-beta.1 + updater 插件预留

- package.json / tauri.conf.json: version 更新为 0.9.0-beta.1
- tauri.conf.json: 添加 plugins.updater 空壳配置 + createUpdaterArtifacts
- Cargo.toml: 添加 tauri-plugin-updater 依赖
- lib.rs: 注册 updater 插件 (空壳，部署时配置 HTTPS 端点 + Ed25519 密钥)

desktop/src-tauri/Cargo.toml

@@ -36,6 +36,7 @@ zclaw-protocols = { workspace = true }
 # Tauri
 tauri = { version = "2", features = [] }
 tauri-plugin-opener = "2"
+tauri-plugin-updater = "2"
 
 # MCP debug plugin (dev-only, allows AI agents to interact with the app)
 tauri-plugin-mcp = { git = "https://github.com/P3GLEG/tauri-plugin-mcp" }