diff --git a/.trellis/tasks/09-26-approve-success-state-unchanged/implement.md b/.trellis/tasks/09-26-approve-success-state-unchanged/implement.md
index 8303778a..6d070f32 100644
--- a/.trellis/tasks/09-26-approve-success-state-unchanged/implement.md
+++ b/.trellis/tasks/09-26-approve-success-state-unchanged/implement.md
@@ -1,4 +1,13 @@
-## 2026-09-26 调查进度（当前）
+## 2026-09-26 根因确认与修复（当前）
+
+- [x] 带诊断复现命中（CG-20260926-0006，任务 48d14805）：浏览器 01.973 发 GET，**05.049 收到 pending**；服务端 02.255 收到同一 GET，**05.598 才读库且读到 completed**。浏览器拿到的响应早于服务端读库，来源只能是 Service Worker 缓存。
+- [x] 根因：`client/vite.config.ts` 的 `app-api-runtime` 规则对 `/api/me`、`/api/workflow/tasks*`、`/api/workflow/approvers*`、`/api/notifications*` 用 `NetworkFirst` + `networkTimeoutSeconds: 3`；网络响应超过 3 秒时 SW 返回审批前缓存的旧响应，真实响应被丢弃。自 2026-03 P21PWA2（9112383d）起存在，生产同样受影响（慢网络/企微手机下审批后页面显示未通过，再点报「已处理」，待办列表可能显示已处理单据）。审批写入本身从未丢失。
+- [x] 修复：去掉 `networkTimeoutSeconds`，仅网络失败（离线）才回退缓存；退出登录清理该缓存（`client/src/pwa.ts:201`）不变。新增 `server/tests/unit/utils/client-pwa-api-cache.test.js`（有修复通过、去掉修复失败）；构建产物 `dist/sw.js` 已无超时。
+- [ ] 修复后复现脚本 3 轮验证（修复前 3 轮命中 2 轮）。
+- [ ] 通过后 `verify-candidate` 取得 PASS 回执。
+- 后续另议：`/api/workflow/tasks*` 含报销审批内容仍会被 SW 缓存供离线读取，与「报销审批证据不进入离线缓存」口径是否冲突待确认；采购提交事务 P2028 见下方。
+
+## 2026-09-26 调查进度
 
 - [x] 非 managed 复现环境：`research/repro.sh`（需先 `sed` 抽取 run-web-gates.sh 1–929 行并删 9–17 行为 gates-lib.sh；库前缀须 `hyb_oa_webgate_`；直接调用 `prepareAccounts`）。采购 ×6 + permission-direct-access ×6，4 worker，约 13 分钟。
 - [x] 第 1 轮复现命中：CG-20260926-0006 页面停在「待派发」、历史仅「提交」；**保留库中该单 approved、任务 completed/approved、历史 start,approve**。结论：审批写入未丢失，问题在审批后页面刷新拿到/显示旧状态。时序：approve 06.418→09.868(200)，task completed_at 07.948，页面 GET 10.289→13.099(200)。
diff --git a/.trellis/tasks/09-26-approve-success-state-unchanged/prd.md b/.trellis/tasks/09-26-approve-success-state-unchanged/prd.md
index 510cb7dd..67993bb2 100644
--- a/.trellis/tasks/09-26-approve-success-state-unchanged/prd.md
+++ b/.trellis/tasks/09-26-approve-success-state-unchanged/prd.md
@@ -24,7 +24,14 @@
 
 ## Acceptance Criteria
 
-- [ ] 在保留库的环境复现至少一次，并记录失败单据任务/实例/历史的库内真实状态
-- [ ] 给出有证据支撑的根因（代码位置 + 机制），区分测试问题与产品缺陷
-- [ ] 若为产品缺陷：说明影响实体范围，及 `b1d25d3c` 是否同样存在
+- [x] 在保留库的环境复现至少一次，并记录失败单据任务/实例/历史的库内真实状态
+- [x] 给出有证据支撑的根因（代码位置 + 机制），区分测试问题与产品缺陷
+- [x] 若为产品缺陷：说明影响实体范围，及 `b1d25d3c` 是否同样存在（SW 规则覆盖 /api/me、workflow/tasks、approvers、notifications；自 2026-03 9112383d 起存在，生产同样受影响）
 - [ ] 修复后 `verify-candidate` 完整通过（取得 PASS 回执）
+
+## Test Plan
+
+- 回归单测：`server/tests/unit/utils/client-pwa-api-cache.test.js` 锁定 `app-api-runtime` 不得设置网络超时（去掉修复即失败）；`client-pwa-lifecycle.test.js` 保持退出登录清理运行时缓存。
+- 构建产物核对：`client/dist/sw.js` 中 `app-api-runtime` 的 `NetworkFirst` 不含 `networkTimeoutSeconds`。
+- 负载复现：`research/repro.sh`（采购 ×8 + permission-direct-access ×8，4 worker）修复前 3 轮命中 2 轮，修复后 3 轮 0 命中。
+- 完整门禁：`verify-candidate` 取得 PASS 回执。
diff --git a/.trellis/tasks/09-26-approve-success-state-unchanged/task.json b/.trellis/tasks/09-26-approve-success-state-unchanged/task.json
index 65fcac25..671190a1 100644
--- a/.trellis/tasks/09-26-approve-success-state-unchanged/task.json
+++ b/.trellis/tasks/09-26-approve-success-state-unchanged/task.json
@@ -5,7 +5,7 @@
   "description": "verify-candidate 34675e1a/750a184b 在4 worker负载下采购主链路3轮挂2次：经理approve返回200，随后任务详情仍pending且历史无approve；单跑每次通过。需保留数据库负载复现查库，确认是否为新引入并影响全部审批。",
   "status": "planning",
   "dev_type": null,
-  "scope": null,
+  "scope": "pwa-service-worker",
   "package": null,
   "priority": "P1",
   "creator": "shunli",
@@ -20,9 +20,13 @@
   "subtasks": [],
   "children": [],
   "parent": null,
-  "relatedFiles": [],
+  "relatedFiles": [
+    "client/vite.config.ts",
+    "server/tests/unit/utils/client-pwa-api-cache.test.js",
+    "client/src/pwa.ts"
+  ],
   "notes": "",
   "meta": {
     "implementationApproval": "APPROVED_BY_USER_20260926"
   }
-}
\ No newline at end of file
+}
diff --git a/client/vite.config.ts b/client/vite.config.ts
index c094bdce..88bcb4fc 100644
--- a/client/vite.config.ts
+++ b/client/vite.config.ts
@@ -136,10 +136,11 @@ export default defineConfig(({ mode }) => {
                 url.pathname.startsWith("/api/notifications")
               );
             },
+            // Fall back to cache only when the network fails (offline). A network
+            // timeout here served pre-approval task state to slow-but-online clients.
             handler: "NetworkFirst",
             options: {
               cacheName: "app-api-runtime",
-              networkTimeoutSeconds: 3,
               cacheableResponse: {
                 statuses: [200],
               },
diff --git a/server/tests/unit/utils/client-pwa-api-cache.test.js b/server/tests/unit/utils/client-pwa-api-cache.test.js
new file mode 100644
index 00000000..85f2cf0c
--- /dev/null
+++ b/server/tests/unit/utils/client-pwa-api-cache.test.js
@@ -0,0 +1,24 @@
+import { readFileSync } from "node:fs";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+
+const viteConfig = readFileSync(path.resolve(__dirname, "../../../../client/vite.config.ts"), "utf8");
+
+function runtimeCacheRule(cacheName) {
+  const marker = `cacheName: "${cacheName}"`;
+  const at = viteConfig.indexOf(marker);
+  expect(at, `${cacheName} rule must exist`).toBeGreaterThan(-1);
+  const start = viteConfig.lastIndexOf("urlPattern:", at);
+  const end = viteConfig.indexOf("urlPattern:", at);
+  return viteConfig.slice(start, end === -1 ? undefined : end);
+}
+
+describe("client PWA API runtime cache", () => {
+  it("falls back to cached API data only when the network fails, never on a slow response", () => {
+    const rule = runtimeCacheRule("app-api-runtime");
+    expect(rule).toContain('handler: "NetworkFirst"');
+    // A timeout made the service worker answer a post-approval refetch with the
+    // cached pre-approval task after 3s, so the page kept showing "待派发".
+    expect(rule).not.toMatch(/networkTimeoutSeconds/);
+  });
+});