diff --git a/internal/cloud/access-control.test.ts b/internal/cloud/access-control.test.ts
index f9e81c37..24b89703 100644
--- a/internal/cloud/access-control.test.ts
+++ b/internal/cloud/access-control.test.ts
@@ -677,6 +677,186 @@ test("workbench workspace status clears completed AgentRun active trace on read"
   }
 });
 
+test("workbench workspace clears stale continuation after AgentRun thread resume failure", async () => {
+  const staleThreadId = "019e0000-0000-7000-8000-000000000195";
+  const agentRunCalls = [];
+  const createRunInputs = [];
+  const agentSessions = new Map();
+  const agentRunServer = createServer(async (request, response) => {
+    const url = new URL(request.url || "/", "http://127.0.0.1");
+    agentRunCalls.push({ method: request.method, path: url.pathname, search: url.search });
+    const send = (data) => {
+      response.writeHead(200, { "content-type": "application/json" });
+      response.end(`${JSON.stringify({ ok: true, data })}\n`);
+    };
+    if (request.method === "GET" && url.pathname === "/api/v1/runs/run_workspace_thread_resume_failed/events") {
+      return send({ items: [
+        { id: "evt_thread_resume_failed", runId: "run_workspace_thread_resume_failed", seq: 1, type: "terminal_status", payload: { commandId: "cmd_workspace_thread_resume_failed", terminalStatus: "failed" }, createdAt: "2026-06-01T00:00:01.000Z" }
+      ] });
+    }
+    if (request.method === "GET" && url.pathname === "/api/v1/runs/run_workspace_thread_resume_failed/commands/cmd_workspace_thread_resume_failed/result") {
+      return send({
+        runId: "run_workspace_thread_resume_failed",
+        commandId: "cmd_workspace_thread_resume_failed",
+        status: "failed",
+        runStatus: "claimed",
+        commandState: "failed",
+        terminalStatus: "failed",
+        completed: false,
+        failureKind: "thread-resume-failed",
+        failureMessage: `codex app-server thread/resume failed for existing thread: no rollout found for thread id ${staleThreadId}`,
+        lastSeq: 1,
+        sessionRef: { sessionId: "ses_issue195_stale", conversationId: "cnv_issue195_stale", threadId: staleThreadId }
+      });
+    }
+    if (request.method === "POST" && url.pathname === "/api/v1/runs") {
+      const body = await requestJson(request);
+      createRunInputs.push(body);
+      return send({ id: "run_workspace_after_stale", status: "pending", backendProfile: "deepseek", sessionRef: { sessionId: body.sessionRef?.sessionId } });
+    }
+    if (request.method === "POST" && url.pathname === "/api/v1/runs/run_workspace_after_stale/commands") {
+      return send({ id: "cmd_workspace_after_stale", runId: "run_workspace_after_stale", state: "pending", type: "turn", seq: 1 });
+    }
+    if (request.method === "POST" && url.pathname === "/api/v1/runs/run_workspace_after_stale/runner-jobs") {
+      return send({
+        action: "create-kubernetes-job",
+        runId: "run_workspace_after_stale",
+        commandId: "cmd_workspace_after_stale",
+        attemptId: "attempt_workspace_after_stale",
+        runnerId: "runner_workspace_after_stale",
+        namespace: "agentrun-v01",
+        jobName: "agentrun-v01-runner-workspace-after-stale"
+      });
+    }
+    response.writeHead(404, { "content-type": "application/json" });
+    response.end(`${JSON.stringify({ ok: false, message: `unexpected ${request.method} ${url.pathname}` })}\n`);
+  });
+  await new Promise((resolve) => agentRunServer.listen(0, "127.0.0.1", resolve));
+
+  const agentRunPort = agentRunServer.address().port;
+  const accessController = createAccessController({
+    env: {
+      HWLAB_ACCESS_CONTROL_REQUIRED: "1",
+      HWLAB_BOOTSTRAP_ADMIN_USERNAME: "admin",
+      HWLAB_BOOTSTRAP_ADMIN_PASSWORD: "admin-pass"
+    },
+    now: () => "2026-06-01T00:00:00.000Z"
+  });
+  accessController.getAgentSessionByTraceId = async (traceId) => agentSessions.get(traceId) ?? null;
+  const server = createCloudApiServer({
+    env: {
+      HWLAB_ACCESS_CONTROL_REQUIRED: "1",
+      HWLAB_BOOTSTRAP_ADMIN_USERNAME: "admin",
+      HWLAB_BOOTSTRAP_ADMIN_PASSWORD: "admin-pass",
+      HWLAB_CODE_AGENT_ADAPTER: "agentrun-v01",
+      AGENTRUN_MGR_URL: `http://127.0.0.1:${agentRunPort}`,
+      HWLAB_CODE_AGENT_AGENTRUN_ALLOW_NON_K3S_URL: "1",
+      HWLAB_CODE_AGENT_AGENTRUN_SOURCE_COMMIT: "0123456789abcdef0123456789abcdef01234567",
+      HWLAB_CODE_AGENT_DEFAULT_PROVIDER_PROFILE: "deepseek"
+    },
+    accessController,
+    now: () => "2026-06-01T00:00:00.000Z"
+  });
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+
+  try {
+    const { port } = server.address();
+    const adminLogin = await postJson(port, "/auth/login", { username: "admin", password: "admin-pass" });
+    const alice = await postJson(port, "/v1/admin/users", { username: "alice-ws-thread-resume", password: "alice-pass" }, adminLogin.cookie);
+    assert.equal(alice.status, 201);
+    const aliceLogin = await postJson(port, "/auth/login", { username: "alice-ws-thread-resume", password: "alice-pass" });
+    const workspace = await getJson(port, "/v1/workbench/workspace?projectId=prj_device_pod_workbench", aliceLogin.cookie);
+    assert.equal(workspace.status, 200);
+    const conversation = await putJson(port, "/v1/agent/conversations/cnv_issue195_stale", {
+      projectId: "prj_device_pod_workbench",
+      sessionId: "ses_issue195_stale",
+      threadId: staleThreadId,
+      sessionStatus: "active",
+      lastTraceId: "trc_issue195_thread_resume_failed",
+      messages: [{ role: "agent", text: "stale continuation still running", status: "running", traceId: "trc_issue195_thread_resume_failed" }]
+    }, aliceLogin.cookie);
+    assert.equal(conversation.status, 200);
+
+    agentSessions.set("trc_issue195_thread_resume_failed", {
+      id: "ses_issue195_stale",
+      ownerUserId: alice.body.user.id,
+      conversationId: "cnv_issue195_stale",
+      threadId: staleThreadId,
+      status: "active",
+      session: {
+        messageId: "msg_issue195_thread_resume_failed",
+        agentRun: {
+          runId: "run_workspace_thread_resume_failed",
+          commandId: "cmd_workspace_thread_resume_failed",
+          backendProfile: "deepseek",
+          managerUrl: `http://127.0.0.1:${agentRunPort}`,
+          lastSeq: 0,
+          sessionId: "ses_issue195_stale",
+          conversationId: "cnv_issue195_stale",
+          threadId: staleThreadId
+        }
+      },
+      updatedAt: "2026-06-01T00:00:00.000Z"
+    });
+
+    const update = await patchJson(port, `/v1/workbench/workspace/${workspace.body.workspace.workspaceId}`, {
+      expectedRevision: 1,
+      selectedConversationId: "cnv_issue195_stale",
+      selectedAgentSessionId: "ses_issue195_stale",
+      activeTraceId: "trc_issue195_thread_resume_failed",
+      providerProfile: "deepseek",
+      sessionStatus: "running",
+      updatedByClient: "test-suite"
+    }, aliceLogin.cookie);
+    assert.equal(update.status, 200);
+    assert.equal(update.body.workspace.selectedConversationId, "cnv_issue195_stale");
+    assert.equal(update.body.workspace.activeTraceId, "trc_issue195_thread_resume_failed");
+
+    const restored = await getJson(port, "/v1/workbench/workspace?projectId=prj_device_pod_workbench", aliceLogin.cookie);
+    assert.equal(restored.status, 200);
+    assert.equal(restored.body.workspace.activeTraceId, null);
+    assert.equal(restored.body.workspace.selectedConversationId, null);
+    assert.equal(restored.body.workspace.selectedAgentSessionId, null);
+    assert.equal(restored.body.workspace.selectedConversation, null);
+    assert.equal(restored.body.workspace.workspace.sessionStatus, "failed");
+    assert.equal(restored.body.workspace.workspace.lastTraceId, "trc_issue195_thread_resume_failed");
+    assert.equal(restored.body.workspace.workspace.staleContinuationCleared, true);
+    assert.equal(restored.body.workspace.workspace.staleContinuationReason, "thread-resume-failed");
+    assert.equal(restored.body.workspace.workspace.staleConversationId, "cnv_issue195_stale");
+    assert.equal(restored.body.workspace.workspace.staleAgentSessionId, "ses_issue195_stale");
+    assert.equal(restored.body.workspace.workspace.staleThreadId, staleThreadId);
+    assert.equal(restored.body.workspace.workspace.recoveryAction, "new-session-on-next-turn");
+
+    const failedConversation = await getJson(port, "/v1/agent/conversations/cnv_issue195_stale", aliceLogin.cookie);
+    assert.equal(failedConversation.status, 200);
+    assert.equal(failedConversation.body.conversation.status, "failed");
+    assert.equal(failedConversation.body.conversation.threadId, staleThreadId);
+
+    const next = await postJson(port, "/v1/agent/chat", {
+      message: "new turn after stale continuation was cleared",
+      traceId: "trc_issue195_after_stale",
+      workspaceId: workspace.body.workspace.workspaceId,
+      expectedWorkspaceRevision: restored.body.workspace.revision,
+      shortConnection: true
+    }, aliceLogin.cookie, { prefer: "respond-async", "x-trace-id": "trc_issue195_after_stale" });
+    assert.equal(next.status, 202);
+    assert.equal(next.body.status, "running");
+    assert.equal(next.body.traceId, "trc_issue195_after_stale");
+    await waitForCondition(() => createRunInputs.length === 1);
+    assert.equal(createRunInputs.length, 1);
+    assert.notEqual(createRunInputs[0].sessionRef?.threadId, staleThreadId);
+    assert.equal(createRunInputs[0].sessionRef?.threadId, undefined);
+    assert.equal(createRunInputs[0].sessionRef?.conversationId, undefined);
+
+    const afterNext = await getJson(port, "/v1/workbench/workspace?projectId=prj_device_pod_workbench", aliceLogin.cookie);
+    assert.equal(afterNext.body.workspace.activeTraceId, "trc_issue195_after_stale");
+    assert.ok(agentRunCalls.some((call) => call.path === "/api/v1/runs/run_workspace_thread_resume_failed/commands/cmd_workspace_thread_resume_failed/result"));
+  } finally {
+    await new Promise((resolve, reject) => server.close((error) => (error ? reject(error) : resolve())));
+    await new Promise((resolve, reject) => agentRunServer.close((error) => (error ? reject(error) : resolve())));
+  }
+});
+
 test("workbench workspace status repairs terminal selected conversation after active trace was cleared", async () => {
   const agentRunCalls = [];
   const agentSessions = new Map();
@@ -1928,3 +2108,11 @@ async function requestJson(request) {
   const text = Buffer.concat(chunks).toString("utf8").trim();
   return text ? JSON.parse(text) : {};
 }
+
+async function waitForCondition(predicate, timeoutMs = 500) {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    if (predicate()) return;
+    await new Promise((resolve) => setTimeout(resolve, 10));
+  }
+}
diff --git a/internal/cloud/access-control.ts b/internal/cloud/access-control.ts
index 99e6cf91..94e362ed 100644
--- a/internal/cloud/access-control.ts
+++ b/internal/cloud/access-control.ts
@@ -862,17 +862,21 @@ class AccessController {
       if (!isTerminalCodeAgentResult(result)) return workspace;
 
       const now = this.now();
-      const selectedConversationId = safeConversationIdLocal(result.conversationId) ? result.conversationId : workspace.selectedConversationId;
-      const selectedAgentSessionId = safeAgentSessionId(result.sessionId ?? result.session?.sessionId ?? result.sessionReuse?.sessionId) || workspace.selectedAgentSessionId;
+      const staleContinuation = isThreadResumeFailedResult(result);
+      const resultConversationId = safeConversationIdLocal(result.conversationId) ? result.conversationId : workspace.selectedConversationId;
+      const resultAgentSessionId = safeAgentSessionId(result.sessionId ?? result.session?.sessionId ?? result.sessionReuse?.sessionId) || workspace.selectedAgentSessionId;
+      const selectedConversationId = staleContinuation ? null : resultConversationId;
+      const selectedAgentSessionId = staleContinuation ? null : resultAgentSessionId;
       await this.syncTerminalWorkbenchConversation({
         workspace,
         actor,
         result,
         activeTraceId: traceId,
-        selectedConversationId,
-        selectedAgentSessionId,
+        selectedConversationId: resultConversationId,
+        selectedAgentSessionId: resultAgentSessionId,
         now
       });
+      const staleThreadId = threadResumeFailureThreadId(result);
       const updated = await this.store.updateWorkspace?.({
         workspaceId: workspace.id,
         ownerUserId: workspace.ownerUserId,
@@ -890,6 +894,14 @@ class AccessController {
           sessionStatus: terminalWorkbenchSessionStatus(result),
           lastTraceId: traceId,
           syncedTraceStatus: result.status ?? result.agentRun?.terminalStatus ?? null,
+          ...(staleContinuation ? {
+            staleContinuationCleared: true,
+            staleContinuationReason: "thread-resume-failed",
+            staleConversationId: resultConversationId,
+            staleAgentSessionId: resultAgentSessionId,
+            staleThreadId,
+            recoveryAction: "new-session-on-next-turn"
+          } : {}),
           updatedAt: now,
           source: "workbench-status-sync",
           valuesRedacted: true,
@@ -1775,6 +1787,12 @@ function redactedWorkspaceJson(value = {}) {
     providerProfile: textOr(workspace.providerProfile, ""),
     sessionStatus: textOr(workspace.sessionStatus, ""),
     lastTraceId: textOr(workspace.lastTraceId, ""),
+    staleContinuationCleared: workspace.staleContinuationCleared === true,
+    staleContinuationReason: textOr(workspace.staleContinuationReason, ""),
+    staleConversationId: textOr(workspace.staleConversationId, ""),
+    staleAgentSessionId: textOr(workspace.staleAgentSessionId, ""),
+    staleThreadId: textOr(workspace.staleThreadId, ""),
+    recoveryAction: textOr(workspace.recoveryAction, ""),
     messages: Array.isArray(workspace.messages) ? workspace.messages.slice(-50).map(redactConversationMessage).filter(Boolean) : undefined,
     actor: workspace.actor && typeof workspace.actor === "object" ? publicActor(workspace.actor) : undefined,
     updatedAt: textOr(workspace.updatedAt, ""),
@@ -1804,6 +1822,29 @@ function isTerminalCodeAgentResult(result = {}) {
   const terminalStatus = textOr(result.agentRun?.terminalStatus, "").toLowerCase();
   return [status, terminalStatus].some((value) => ["completed", "failed", "blocked", "canceled", "cancelled", "timeout", "error"].includes(value));
 }
+function isThreadResumeFailedResult(result = {}) {
+  const values = [
+    result.error?.code,
+    result.error?.category,
+    result.blocker?.code,
+    result.blocker?.category,
+    result.providerTrace?.failureKind,
+    result.agentRun?.providerTrace?.failureKind,
+    result.agentRun?.failureKind
+  ].map((value) => textOr(value, "").toLowerCase().replace(/_/gu, "-"));
+  return values.some((value) => value === "thread-resume-failed")
+    || /no rollout found for thread id|thread\/resume failed/iu.test(String(result.error?.message ?? result.blocker?.message ?? result.providerTrace?.failureMessage ?? result.agentRun?.providerTrace?.failureMessage ?? ""));
+}
+function threadResumeFailureThreadId(result = {}) {
+  return boundedText(textOr(
+    result.providerTrace?.threadId
+      ?? result.agentRun?.providerTrace?.threadId
+      ?? result.session?.threadId
+      ?? result.sessionReuse?.threadId
+      ?? result.threadId,
+    ""
+  ), 240) || null;
+}
 function terminalWorkbenchSessionStatus(result = {}) {
   const sessionStatus = textOr(result.session?.status ?? result.sessionSummary?.status ?? result.sessionLifecycleStatus ?? result.runnerTrace?.sessionStatus, "").toLowerCase();
   if (sessionStatus && sessionStatus !== "running" && sessionStatus !== "busy" && sessionStatus !== "pending") return sessionStatus === "cancelled" ? "canceled" : sessionStatus;
diff --git a/internal/cloud/code-agent-agentrun-adapter.ts b/internal/cloud/code-agent-agentrun-adapter.ts
index d6c30d67..78ab76cc 100644
--- a/internal/cloud/code-agent-agentrun-adapter.ts
+++ b/internal/cloud/code-agent-agentrun-adapter.ts
@@ -795,7 +795,7 @@ function agentRunFailureAttribution({ code, message, canceled = false } = {}) {
     return {
       category: "thread_resume_failed",
       retryable: true,
-      userMessage: "AgentRun 复用的 Codex thread 已失效；当前标准是终止本轮并保留原 session 指针，不启动新的 thread/start，也不拼接历史上下文。请重新发起新会话。",
+      userMessage: "AgentRun 复用的 Codex thread 已失效；当前 turn 会按失败终止，Workbench 会清理 stale continuation 指针，下一轮自动从新 session/thread 启动。",
       summary: message || "AgentRun thread/resume failed for an existing thread."
     };
   }