diff --git a/frontend/components/account/AccountCenter.tsx b/frontend/components/account/AccountCenter.tsx
index dbf82d8a..913eb8e6 100644
--- a/frontend/components/account/AccountCenter.tsx
+++ b/frontend/components/account/AccountCenter.tsx
@@ -2,7 +2,6 @@
 
 import { useCallback, useEffect, useMemo, useState } from "react";
 import Link from "next/link";
-import dynamic from "next/dynamic";
 import { useRouter } from "next/navigation";
 import type { User } from "@supabase/supabase-js";
 import {
@@ -48,17 +47,7 @@ import {
 } from "@/lib/payment-host";
 import { trackAppEvent } from "@/lib/app-analytics";
 import { useI18n } from "@/hooks/useI18n";
-
-const UnlockProOverlay = dynamic(
-  () =>
-    import("@/components/subscription/UnlockProOverlay").then(
-      (module) => module.UnlockProOverlay,
-    ),
-  {
-    ssr: false,
-    loading: () => null,
-  },
-);
+import { UnlockProOverlay } from "@/components/subscription/UnlockProOverlay";
 
 // --- Types ---
 
diff --git a/frontend/components/account/__tests__/paymentShell.test.ts b/frontend/components/account/__tests__/paymentShell.test.ts
new file mode 100644
index 00000000..a525f687
--- /dev/null
+++ b/frontend/components/account/__tests__/paymentShell.test.ts
@@ -0,0 +1,35 @@
+import fs from "node:fs";
+import path from "node:path";
+
+function assert(condition: unknown, message: string) {
+  if (!condition) throw new Error(message);
+}
+
+export function runTests() {
+  const projectRoot = process.cwd();
+  const accountCenterPath = path.join(
+    projectRoot,
+    "components",
+    "account",
+    "AccountCenter.tsx",
+  );
+  const serviceWorkerPath = path.join(projectRoot, "public", "sw.js");
+
+  const accountCenterSource = fs.readFileSync(accountCenterPath, "utf8");
+  const serviceWorkerSource = fs.readFileSync(serviceWorkerPath, "utf8");
+
+  assert(
+    accountCenterSource.includes(
+      'import { UnlockProOverlay } from "@/components/subscription/UnlockProOverlay";',
+    ),
+    "checkout overlay must be in the account bundle, not lazy-loaded after the user clicks pay",
+  );
+  assert(
+    !/const\s+UnlockProOverlay\s*=\s*dynamic\s*\(/.test(accountCenterSource),
+    "checkout overlay must not be dynamically imported; stale deployments can make the lazy chunk fail at pay time",
+  );
+  assert(
+    !/STATIC_ASSETS\s*=\s*\[[^\]]*["']\/_next\//s.test(serviceWorkerSource),
+    "service worker must not cache-first the whole /_next/ tree; stale chunks break checkout after deploys",
+  );
+}
diff --git a/frontend/public/sw.js b/frontend/public/sw.js
index f0be9bf1..394a47e8 100644
--- a/frontend/public/sw.js
+++ b/frontend/public/sw.js
@@ -1,5 +1,14 @@
-const CACHE_NAME = "polyweather-v1";
-const STATIC_ASSETS = ["/_next/", "/favicon"];
+const CACHE_NAME = "polyweather-v2";
+const CACHEABLE_PUBLIC_ASSETS = [
+  "/favicon.ico",
+  "/favicon-16x16.png",
+  "/favicon-32x32.png",
+  "/apple-touch-icon.png",
+  "/android-chrome-192x192.png",
+  "/android-chrome-512x512.png",
+  "/manifest.webmanifest",
+  "/site.webmanifest",
+];
 
 self.addEventListener("install", (event) => {
   event.waitUntil(self.skipWaiting());
@@ -7,18 +16,27 @@ self.addEventListener("install", (event) => {
 
 self.addEventListener("activate", (event) => {
   event.waitUntil(
-    caches.keys().then((keys) =>
-      Promise.all(
-        keys.filter((key) => key !== CACHE_NAME).map((key) => caches.delete(key)),
-      ),
-    ),
+    caches
+      .keys()
+      .then((keys) =>
+        Promise.all(
+          keys
+            .filter((key) => key !== CACHE_NAME)
+            .map((key) => caches.delete(key)),
+        ),
+      )
+      .then(() => self.clients.claim()),
   );
 });
 
 self.addEventListener("fetch", (event) => {
   const url = new URL(event.request.url);
 
-  if (STATIC_ASSETS.some((prefix) => url.pathname.startsWith(prefix))) {
+  // Do not cache-first Next.js build chunks. A user can keep an old app shell
+  // open across deployments; if checkout UI is loaded later, stale/missing
+  // chunks surface as a generic page fault. Let the browser/Vercel handle
+  // immutable _next/static asset caching instead.
+  if (CACHEABLE_PUBLIC_ASSETS.includes(url.pathname)) {
     event.respondWith(
       caches.open(CACHE_NAME).then((cache) =>
         cache.match(event.request).then(
diff --git a/frontend/scripts/run-business-state-tests.mjs b/frontend/scripts/run-business-state-tests.mjs
index 74e1ec3d..3c498a88 100644
--- a/frontend/scripts/run-business-state-tests.mjs
+++ b/frontend/scripts/run-business-state-tests.mjs
@@ -84,7 +84,7 @@ function collectTests(dir) {
   });
 }
 
-const testsRoot = path.join(projectRoot, "components", "dashboard", "scan-terminal", "__tests__");
+const testsRoot = path.join(projectRoot, "components");
 const testFiles = fs.existsSync(testsRoot) ? collectTests(testsRoot).sort() : [];
 
 if (!testFiles.length) {