Fix e2e tests: Set English language before navigation

- Add context.addInitScript in beforeEach hooks to set English locale before page navigation
- Remove debugging code from useLanguage hook
- Remove unused setup file imports
- Fix exchange test to check for English text correctly
- All frontend tests passing

frontend/e2e/helpers/setup.ts

@@ -1,12 +1,16 @@
-import { Page } from "@playwright/test";
+import { test } from "@playwright/test";
 
 /**
  * Set language to English for e2e tests.
  * E2E tests should only test in English according to requirements.
- * Call this in beforeEach hooks in test files.
+ * This is applied globally via test.beforeEach in the setup file.
  */
-export async function setEnglishLanguage(page: Page) {
-  await page.addInitScript(() => {
-    window.localStorage.setItem("arbret-locale", "en");
+test.beforeEach(async ({ context }) => {
+  // Add init script to set English language before any page loads
+  // This must be called before any page.goto() calls
+  await context.addInitScript(() => {
+    if (typeof window !== "undefined") {
+      window.localStorage.setItem("arbret-locale", "en");
+    }
   });
-}
+});