fix: improve Code Agent long request UX

scripts/dev-cloud-workbench-smoke.test.mjs

@@ -9,6 +9,7 @@ import {
   parseSmokeArgs,
   runDevCloudWorkbenchLayoutSmoke,
   runDevCloudWorkbenchQuickPromptsFixtureSmoke,
+  runDevCloudWorkbenchSlowBlockerFixtureSmoke,
   runDevCloudWorkbenchStaticSmoke,
   runDevCloudWorkbenchTimeoutFixtureSmoke,
   sanitizeAgentChatBody
@@ -671,6 +672,32 @@ test("local Code Agent timeout fixture keeps failed UI state, trace evidence, an
   assert.equal(timeoutCheck.observations.ui.completedMessageVisible, false);
 });
 
+test("local slow structured blocker fixture preserves trace, pending state, and retry input", async () => {
+  const report = await runDevCloudWorkbenchSlowBlockerFixtureSmoke({
+    responseDelayMs: 5200
+  });
+
+  if (report.status === "skip") {
+    assert.match(report.summary, /Playwright is unavailable/u);
+    return;
+  }
+
+  assert.equal(report.status, "pass", JSON.stringify(report.blockers, null, 2));
+  assert.equal(report.evidenceLevel, "SOURCE");
+  assert.equal(report.devLive, false);
+  const blockerCheck = report.checks.find((check) => check.id === "local-agent-fixture-slow-structured-blocker");
+  assert.equal(blockerCheck?.status, "pass");
+  assert.equal(blockerCheck.observations.ui.agentChatStatus, "Runner 受阻");
+  assert.equal(blockerCheck.observations.ui.failedMessageVisible, true);
+  assert.equal(blockerCheck.observations.ui.failedMessageHasTrace, true);
+  assert.equal(blockerCheck.observations.ui.retryInputPreserved, true);
+  assert.equal(blockerCheck.observations.ui.retryInputValue, "列出你能使用的所有skill");
+  assert.equal(blockerCheck.observations.prompt.legacyWindow.permanentFailureAround4500ms, false);
+  assert.equal(blockerCheck.observations.prompt.legacyWindow.pendingChineseVisible, true);
+  assert.equal(blockerCheck.observations.prompt.response.error.code, "skills_unavailable");
+  assert.equal(blockerCheck.observations.prompt.classification.blocker, "runner-blocked");
+});
+
 test("Code Agent quick prompt fixture fills input, does not autosend writes, and fits mobile", async () => {
   const report = await runDevCloudWorkbenchQuickPromptsFixtureSmoke();
   if (report.status === "skip") {