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/e2e/smoke.spec.ts

@@ -0,0 +1,10 @@
+import { test, expect } from "./fixtures";
+
+test("app loads with the persona nav and composer", async ({ page }) => {
+  await page.goto("/");
+  await expect(page.getByText("OpenWorker").first()).toBeVisible();
+  // New session + Search are the fixed top nav.
+  await expect(page.getByRole("button", { name: /New session/i })).toBeVisible();
+  // The persona groups render from /v1/personas.
+  await expect(page.getByText("Ops", { exact: true })).toBeVisible();
+});