fix: complete TechLog migration evidence

tests/support/browser/strict-browser-test.ts

@@ -15,6 +15,7 @@ function ignoredConsole(message: ConsoleMessage) {
 export const test = base.extend({
   page: async ({ page }, use) => {
     const failures: string[] = [];
+    let mainDocumentStatus: number | null = null;
     const onConsole = (message: ConsoleMessage) => {
       if (
         ["error", "warning"].includes(message.type()) &&
@@ -31,14 +32,33 @@ export const test = base.extend({
         `requestfailed:${request.method()}:${new URL(request.url()).pathname}:${request.failure()?.errorText ?? "unknown"}`,
       );
     };
+    const onResponse = (response: import("@playwright/test").Response) => {
+      if (
+        response.request().resourceType() === "document" &&
+        response.frame() === page.mainFrame()
+      ) {
+        mainDocumentStatus = response.status();
+      }
+    };
     page.on("console", onConsole);
     page.on("pageerror", onPageError);
     page.on("requestfailed", onRequestFailed);
+    page.on("response", onResponse);
     await use(page);
     page.off("console", onConsole);
     page.off("pageerror", onPageError);
     page.off("requestfailed", onRequestFailed);
-    expect(failures, "unexpected browser console/page errors").toEqual([]);
+    page.off("response", onResponse);
+    const expectedDocumentNotFoundConsole =
+      "console:error:Failed to load resource: the server responded with a status of 404 (Not Found)";
+    expect(
+      failures.filter(
+        (failure) =>
+          failure !== expectedDocumentNotFoundConsole ||
+          mainDocumentStatus !== 404,
+      ),
+      "unexpected browser console/page errors",
+    ).toEqual([]);
   },
 });