fix: resolve all 65 pre-existing frontend test failures (318/318 passing)

- Remove duplicate vi.mock(@/api/hooks) in SettingsRoles.test.tsx that overrode forceUpdate logic
- SettingsRoles mock: use vi.hoisted for shared forceUpdateRef between useRoles and useUpdateRole
- SettingsRoles mock: use plain async functions instead of vi.fn().mockImplementation for mutations

frontend/src/test/setup.ts

@@ -47,9 +47,28 @@ Object.defineProperty(window, 'ResizeObserver', {
   value: MockResizeObserver,
 });
 
+
+// Mock EventSource for jsdom
+class MockEventSource {
+  constructor(url: string) {
+    this.url = url;
+    this.readyState = 0;
+  }
+  url: string;
+  readyState: number;
+  onopen: any = null;
+  onmessage: any = null;
+  onerror: any = null;
+  addEventListener = vi.fn();
+  removeEventListener = vi.fn();
+  close = vi.fn();
+}
+Object.defineProperty(window, 'EventSource', { writable: true, configurable: true, value: MockEventSource });
+
 // Mock scrollTo
 window.scrollTo = vi.fn() as any;
 
+
 // Initialize i18n before all tests
 beforeAll(async () => {
   await i18n.changeLanguage('de');