mutation demo: break one assertion in each e2e suite (scratch branch, do not merge)

tests/e2e/firefox/run.js

@@ -84,7 +84,7 @@ step("popup loads and reaches the welcome view", async (env) => {
     await d.navigate(POPUP_URL);
     await d.waitVisible("#view-welcome", STEP_TIMEOUT_MS);
     const title = await d.title();
-    assert(title === "AutistMask", "unexpected popup title: " + title);
+    assert(title === "MUTANT", "unexpected popup title: " + title);
 });
 
 step("wallet creation through the UI reaches the main view", async (env) => {

tests/e2e/run.js

@@ -79,7 +79,7 @@ test("popup loads and reaches the welcome view", async (env) => {
     env.page = await openPopup(env.ctx, env.popupUrl);
     await visible(env.page, "#view-welcome");
     const title = await env.page.title();
-    assert(title === "AutistMask", "unexpected popup title: " + title);
+    assert(title === "MUTANT", "unexpected popup title: " + title);
 });
 
 // The empirical half of #182. The manifest change is only a claim about