diff --git a/docs/tests.md b/docs/tests.md
index ecd1f58..011c273 100644
--- a/docs/tests.md
+++ b/docs/tests.md
@@ -73,6 +73,18 @@ npm run test:frontend
 
 Runs the Playwright smoke test for browser-level shared-state sync. This is also the only suite that can cover the Configure sampler preset panel, because `renderFlags()` destroys and rebuilds it — the `<select>` an assertion reads is a different element than the one that was clicked, which a `node:vm` harness cannot reproduce.
 
+On Windows, Codex's sandbox can redirect `LOCALAPPDATA`, causing Playwright to
+look in an empty browser cache even when Chromium is installed for the normal
+user. `PLAYWRIGHT_BROWSERS_PATH` can select an existing cache (see
+[Playwright's browser cache documentation](https://playwright.dev/docs/browsers#managing-browser-binaries)),
+but this alone does not grant network access. If Chromium reports
+`ERR_NETWORK_ACCESS_DENIED` when opening the local fixture server, run
+`npm run test:frontend` through Codex's approved command escalation or a normal
+local terminal. Do not repeatedly reinstall browsers into the redirected cache.
+The pop-out fixtures register server and browser cleanup immediately after each
+resource starts, so setup failures exit promptly; a child-process regression
+check verifies this with an intentionally missing Chromium cache.
+
 Both browser suites serve `ui/` through the shared Node HTTP/1.1 server in `tests/frontend/ui_server.cjs`. Persistent connections avoid opening a socket for every asset, which can exhaust Windows socket buffers during repeated page loads (`net::ERR_NO_BUFFER_SPACE`). A regression check verifies that HTML, JavaScript, and CSS requests reuse one connection. Python is not needed to serve the browser fixtures.
 
 The browser suite has named `node:test` scenarios with fresh browser contexts and API fixtures. Shared controls, authentication, inference, Chat streaming/recovery/compaction, samplers, external servers, custom launch arguments, backend activation, model switching, preset focus, model folders, and Monitor behavior run independently. A scenario failure does not prevent the remaining scenarios from running. Smoke-test failures, including startup and reload timeouts, retain the original error as their cause and include captured page errors and failed requests, or explicit indications that none were captured. Normal request cancellations during navigation are excluded. Injected Configure rendering failures and connection resets verify these diagnostics on both initial load and reload. The external-server reload check waits for a restored inference target before asserting its exact identity, so a wrong identity is reported directly. To run one scenario:
diff --git a/tests/frontend/chat_popout_integration.cjs b/tests/frontend/chat_popout_integration.cjs
index 94707f5..3bfa590 100644
--- a/tests/frontend/chat_popout_integration.cjs
+++ b/tests/frontend/chat_popout_integration.cjs
@@ -2,6 +2,8 @@ const assert = require("node:assert/strict");
 const fs = require("node:fs");
 const path = require("node:path");
 const { randomUUID } = require("node:crypto");
+const { spawnSync } = require("node:child_process");
+const os = require("node:os");
 const { test } = require("node:test");
 const { startUiServer } = require("./ui_server.cjs");
 
@@ -25,6 +27,21 @@ const CHAT_HOST_STATUS = "#chat-window-host-status";
 const CHAT_OPEN_FULL_GUI = "#chat-window-open-full-gui";
 const API_SECRET = "fixture-api-secret-must-not-persist";
 
+test("browser launch failure closes the fixture server", { timeout: 15_000 }, () => {
+    const env = { ...process.env, PLAYWRIGHT_BROWSERS_PATH: path.join(os.tmpdir(), randomUUID()) };
+    delete env.NODE_TEST_CONTEXT;
+    const result = spawnSync(process.execPath, [
+        "--test", "--test-name-pattern=^direct Chat window URL", __filename,
+    ], {
+        env,
+        encoding: "utf8",
+        timeout: 10_000,
+    });
+    assert.ifError(result.error);
+    assert.equal(result.status, 1, "missing Chromium must fail promptly rather than hang");
+    assert.match(result.stdout + result.stderr, /Executable doesn't exist/);
+});
+
 function json(value) {
     return JSON.stringify(value);
 }
@@ -243,17 +260,14 @@ async function assertNoSecret(page, label) {
 
 test("direct Chat window URL without an opener shows a safe unavailable shell", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const callsResult = await installApiRoutes(context);
     const pageErrors = [];
     const page = await context.newPage();
     page.on("pageerror", error => pageErrors.push(error.message));
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     await page.goto(`${server.baseUrl}?${POPUP_QUERY}`, { waitUntil: "domcontentloaded" });
     await page.locator(CHAT_WINDOW_PLACEHOLDER).waitFor({ state: "visible" });
@@ -280,17 +294,14 @@ test("direct Chat window URL without an opener shows a safe unavailable shell",
 
 test("Chat pop-out contains URL construction and live host getter failures", { timeout: 60_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const pageErrors = [];
     context.on("page", page => page.on("pageerror", error => pageErrors.push(error.message)));
     await installInitScript(context, representativeConversation(), randomUUID());
     const { calls } = await installApiRoutes(context);
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
     const main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
     await selectChat(main);
@@ -334,7 +345,9 @@ test("Chat pop-out contains URL construction and live host getter failures", { t
 
 test("Chat recovery focuses a safe control when no server disables the composer", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     await installInitScript(context, representativeConversation(), randomUUID());
     await installApiRoutes(context, {
@@ -345,11 +358,6 @@ test("Chat recovery focuses a safe control when no server disables the composer"
             runtime_generation: null,
         },
     });
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     const main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -382,15 +390,12 @@ test("Chat recovery focuses a safe control when no server disables the composer"
 
 test("Recover chat here explains ownership contention and retries after the owner closes", { timeout: 60_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     await installInitScript(context, representativeConversation(), randomUUID());
     const { calls } = await installApiRoutes(context);
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     const owner = await context.newPage();
     await owner.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -437,7 +442,9 @@ test("Recover chat here explains ownership contention and retries after the owne
 
 test("Chat initialization failure leaves an unavailable shell without breaking the GUI", { timeout: 60_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     let chatUiRouteHit = false;
     await context.route(/\/js\/chat\/chat-main\.js(?:\?|$)/, async route => {
@@ -452,11 +459,6 @@ test("Chat initialization failure leaves an unavailable shell without breaking t
     const pageErrors = [];
     const page = await context.newPage();
     page.on("pageerror", error => pageErrors.push(error.message));
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     await page.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
     await page.waitForFunction(() => window.__phase4ChatInitFailureFixture === true);
@@ -480,7 +482,9 @@ test("Chat initialization failure leaves an unavailable shell without breaking t
 
 test("real same-context Chat pop-out use and return cycle", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const pageErrors = [];
     context.on("page", page => page.on("pageerror", error => pageErrors.push(error.message)));
@@ -490,11 +494,6 @@ test("real same-context Chat pop-out use and return cycle", { timeout: 120_000 }
     const { calls } = await installApiRoutes(context);
     let main;
     let popup;
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -695,7 +694,9 @@ test("real same-context Chat pop-out use and return cycle", { timeout: 120_000 }
 
 test("blocked and blank pop-outs preserve ownership and a fresh transfer identity", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const pageErrors = [];
     context.on("page", page => page.on("pageerror", error => pageErrors.push(error.message)));
@@ -712,11 +713,6 @@ test("blocked and blank pop-outs preserve ownership and a fresh transfer identit
     });
     const { calls } = await installApiRoutes(context);
     let main;
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -895,7 +891,9 @@ test("blocked and blank pop-outs preserve ownership and a fresh transfer identit
 
 test("idle popup close and deletion recovery use an independently seeded transcript", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     await context.addInitScript(() => { window.__LLAMA_GUI_TEST_HOOKS__ = true; });
     const pageErrors = [];
@@ -903,11 +901,6 @@ test("idle popup close and deletion recovery use an independently seeded transcr
     const conversation = representativeConversation();
     await installInitScript(context, conversation, `phase4-idle-${randomUUID()}`);
     const { calls } = await installApiRoutes(context);
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     const main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -1034,7 +1027,9 @@ test("idle popup close and deletion recovery use an independently seeded transcr
 
 test("popup reload and main reload recover the newest checkpoint without resend", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({ headless: true });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const conversation = representativeConversation();
     const runNonce = `phase4-reload-${randomUUID()}`;
@@ -1043,11 +1038,6 @@ test("popup reload and main reload recover the newest checkpoint without resend"
     const { calls } = await installApiRoutes(context);
     let main;
     let popup;
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     main = await context.newPage();
     await main.goto(server.baseUrl, { waitUntil: "domcontentloaded" });
@@ -1179,21 +1169,18 @@ test("popup reload and main reload recover the newest checkpoint without resend"
 
 test("insecure mapped origin keeps single-window Chat fallback usable", { timeout: 120_000 }, async t => {
     const server = await startUiServer();
+    t.after(() => server.close());
     const browser = await chromium.launch({
         headless: true,
         args: ["--host-resolver-rules=MAP popout-test.invalid 127.0.0.1"],
     });
+    t.after(() => browser.close());
     const context = await browser.newContext();
     const conversation = representativeConversation();
     const runNonce = `phase4-insecure-${randomUUID()}`;
     await installInitScript(context, conversation, runNonce);
     await installApiRoutes(context);
     const main = await context.newPage();
-    t.after(async () => {
-        await context.close();
-        await browser.close();
-        await server.close();
-    });
 
     const port = new URL(server.baseUrl).port;
     await main.goto(`http://popout-test.invalid:${port}/`, { waitUntil: "domcontentloaded" });