feat: OpenMesh 基础平台与 MD/PDF 转换技能

- 后端: coworker 智能体框架, WS API, 文件上传, 附件处理
- 前端: Open WebUI, 文件全量走 upload API (含 MD/TXT/JSON 等文本类)
- 技能: md-to-office (pandoc + wkhtmltopdf)
- 修复: 上传文件路径丢失, Agent 搜索浪费, 输出文件跑到 uploads/
- 打包: PyInstaller one-dir, 预打包 pandoc/wkhtmltopdf/chromium

surfaces/gui/src-tauri/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "openworker-desktop"
+version = "0.1.0"
+description = "OpenWorker desktop shell"
+edition = "2021"
+rust-version = "1.77"
+
+[lib]
+name = "openworker_desktop_lib"
+crate-type = ["staticlib", "cdylib", "rlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", features = ["tray-icon"] }
+tauri-plugin-dialog = "2"
+tauri-plugin-autostart = "2"
+tauri-plugin-single-instance = "2"
+tauri-plugin-updater = "2"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+uuid = { version = "1", features = ["v4"] }
+# Kept outside the Tauri shell so another product can depend on the same local STT engine.
+ocw-stt = { path = "../../../stt" }