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/error-retry.spec.ts

@@ -0,0 +1,49 @@
+// Model-layer roadmap item 1 (2026-07-22): a turn that dies on a provider error leaves a
+// visible, persistent marker with a Retry affordance. Retry re-runs the failed turn with NO
+// new user bubble; once the turn recovers, the button disappears (the notice is history).
+import { expect } from "@playwright/test";
+import { test } from "./fixtures";
+
+test("provider error shows a retriable notice; Retry re-runs without a new user message", async ({
+  page,
+}) => {
+  await page.goto("/");
+  await page.getByText("Draft the launch note").first().click();
+  const box = page.getByPlaceholder(/Ask the coworker/);
+  await box.fill("please fail the turn");
+  await box.press("Enter");
+
+  await expect(page.getByText("Error: model unreachable").first()).toBeVisible({ timeout: 10_000 });
+  const retry = page.getByTestId("notice-retry");
+  await expect(retry).toBeVisible();
+
+  await retry.click();
+  await expect(page.getByText("Recovered after retry.").first()).toBeVisible({ timeout: 10_000 });
+
+  // No fake user bubble from the retry turn, exactly one real one…
+  await expect(page.locator(".bubble-user")).toHaveCount(1);
+  // …and the button is gone now that the error notice is no longer the transcript tail.
+  await expect(page.getByTestId("notice-retry")).toHaveCount(0);
+});
+
+test("Retry survives a model switch — the intended recovery path", async ({ page }) => {
+  await page.goto("/");
+  await page.getByText("Draft the launch note").first().click();
+  const box = page.getByPlaceholder(/Ask the coworker/);
+  await box.fill("please fail the turn");
+  await box.press("Enter");
+  await expect(page.getByTestId("notice-retry")).toBeVisible({ timeout: 10_000 });
+
+  // Switch models: the info marker lands AFTER the error — Retry must stay offered
+  // (owner-hit 2026-07-23: the switch notices consumed it).
+  const picker = page.locator(".dd").filter({ hasText: "Claude Opus 4.8" });
+  await picker.locator(".pill").click();
+  await page.locator(".dd-item").filter({ hasText: "GPT-5.5" }).click();
+  await expect(page.getByText(/Model switched to gpt-5.5/).first()).toBeVisible();
+  const retry = page.getByTestId("notice-retry");
+  await expect(retry).toBeVisible();
+
+  await retry.click();
+  await expect(page.getByText("Recovered after retry.").first()).toBeVisible({ timeout: 10_000 });
+  await expect(page.getByTestId("notice-retry")).toHaveCount(0);
+});