diff --git a/cloud/console-react/src/api/chv.closeup.test.ts b/cloud/console-react/src/api/chv.closeup.test.ts
index 47adda4..ed7d758 100644
--- a/cloud/console-react/src/api/chv.closeup.test.ts
+++ b/cloud/console-react/src/api/chv.closeup.test.ts
@@ -69,8 +69,17 @@ describe("附件拦截与排队提示边角（closeup）", () => {
 });
 
 describe("isWorkerAlive 边界（closeup）", () => {
-  it("last_seen 恰好 120 秒算在线（<=120）", () => {
+  // 精确边界不用活时钟测：原写法先取 Date.now() 再让被测函数
+  // 内部重取一次时钟，age = 120 + 两次取时钟的差，两次取时钟
+  // 跨过毫秒边界时 age = 120.001，<=120 判定为 false，约 7%
+  // 概率抖动（30 轮 2 败，均是本用例）。生产逻辑 <=120 本身
+  // 没错，错的是用活时钟测精确边界。
+  it("恰好 120 秒算在线（<=120，用不取时钟的字段确定性测）", () => {
+    expect(isWorkerAlive({ executor: "cloud-hypervisor", last_seen_seconds_ago: 120 })).toBe(true);
+    expect(isWorkerAlive({ executor: "cloud-hypervisor", last_seen_seconds_ago: 121 })).toBe(false);
+  });
+  it("活时钟只测带 1 秒余量的内侧，不测精确边界", () => {
     const now = Date.now() / 1000;
-    expect(isWorkerAlive({ executor: "cloud-hypervisor", last_seen: now - 120 })).toBe(true);
+    expect(isWorkerAlive({ executor: "cloud-hypervisor", last_seen: now - 119 })).toBe(true);
   });
 });