frontend: fix linting

Author: ffreddow

frontend/src/pages/__tests__/Tokens.test.tsx

@@ -30,10 +30,6 @@ describe('Tokens Component', () => {
   });
 
   it('renders loading spinner initially', () => {
-    (fetchClient.GET as unknown as Mock).mockImplementation(() =>
-      new Promise(() => {}) // Never resolves
-    );
-
     render(<Tokens />);
     expect(screen.getByText('Loading...')).toBeTruthy();
   });

frontend/src/utils.tsx

@@ -156,7 +156,7 @@ export async function storeSecretKeyInServiceWorker(secretKey: string): Promise<
                     clearTimeout(timeout);
                     navigator.serviceWorker.removeEventListener('message', handleMessage);
                     storeSecretKeyPromise = null;
-                    reject("Failed to store secretKey in Service Worker: " + msg.data);
+                    reject(`Failed to store secretKey in Service Worker: ${msg.data}`);
                     return;
                 }
                 clearTimeout(timeout);