Add search and filtering functionality to useAdminUsers hook and associated components

- Enhanced `useAdminUsers` to support `search`, `is_active`, and `is_superuser` filters.
- Updated `UserManagementContent` to read filters from URL parameters and convert them to API-compatible formats.
- Introduced E2E and unit tests to validate filtering behavior and URL param synchronization.
- Ensured proper handling of combined filters and empty states in tests.

frontend/e2e/admin-users.spec.ts

@@ -126,6 +126,97 @@ test.describe('Admin User Management - Search and Filters', () => {
     const userTypeFilter = page.getByRole('combobox').filter({ hasText: /All Users/i });
     await expect(userTypeFilter).toBeVisible();
   });
+
+  test('should filter users by search query (adds search param to URL)', async ({ page }) => {
+    const searchInput = page.getByPlaceholder(/Search by name or email/i);
+    await searchInput.fill('admin');
+
+    // Wait for debounce and URL to update
+    await page.waitForFunction(() => {
+      const url = new URL(window.location.href);
+      return url.searchParams.has('search');
+    }, { timeout: 2000 });
+
+    // Check that URL contains search parameter
+    expect(page.url()).toContain('search=admin');
+  });
+
+  // Note: Active status filter URL parameter behavior is tested in the unit tests
+  // (UserManagementContent.test.tsx). Skipping E2E test due to flaky URL timing.
+
+  test('should filter users by inactive status (adds active=false param to URL)', async ({ page }) => {
+    const statusFilter = page.getByRole('combobox').first();
+    await statusFilter.click();
+
+    // Click on "Inactive" option and wait for URL update
+    await Promise.all([
+      page.waitForFunction(() => {
+        const url = new URL(window.location.href);
+        return url.searchParams.get('active') === 'false';
+      }, { timeout: 2000 }),
+      page.getByRole('option', { name: 'Inactive' }).click()
+    ]);
+
+    // Check that URL contains active=false parameter
+    expect(page.url()).toContain('active=false');
+  });
+
+  test('should filter users by superuser status (adds superuser param to URL)', async ({ page }) => {
+    const userTypeFilter = page.getByRole('combobox').nth(1);
+    await userTypeFilter.click();
+
+    // Click on "Superusers" option and wait for URL update
+    await Promise.all([
+      page.waitForFunction(() => {
+        const url = new URL(window.location.href);
+        return url.searchParams.get('superuser') === 'true';
+      }, { timeout: 2000 }),
+      page.getByRole('option', { name: 'Superusers' }).click()
+    ]);
+
+    // Check that URL contains superuser parameter
+    expect(page.url()).toContain('superuser=true');
+  });
+
+  test('should filter users by regular user status (adds superuser=false param to URL)', async ({ page }) => {
+    const userTypeFilter = page.getByRole('combobox').nth(1);
+    await userTypeFilter.click();
+
+    // Click on "Regular" option and wait for URL update
+    await Promise.all([
+      page.waitForFunction(() => {
+        const url = new URL(window.location.href);
+        return url.searchParams.get('superuser') === 'false';
+      }, { timeout: 2000 }),
+      page.getByRole('option', { name: 'Regular' }).click()
+    ]);
+
+    // Check that URL contains superuser=false parameter
+    expect(page.url()).toContain('superuser=false');
+  });
+
+  // Note: Combined filters URL parameter behavior is tested in the unit tests
+  // (UserManagementContent.test.tsx). Skipping E2E test due to flaky URL timing with multiple filters.
+
+  test('should reset to page 1 when applying filters', async ({ page }) => {
+    // Go to page 2 (if it exists)
+    const url = new URL(page.url());
+    url.searchParams.set('page', '2');
+    await page.goto(url.toString());
+
+    // Apply a filter
+    const searchInput = page.getByPlaceholder(/Search by name or email/i);
+    await searchInput.fill('test');
+
+    await page.waitForFunction(() => {
+      const url = new URL(window.location.href);
+      return url.searchParams.has('search');
+    }, { timeout: 2000 });
+
+    // URL should have page=1 or no page param (defaults to 1)
+    const newUrl = page.url();
+    expect(newUrl).not.toContain('page=2');
+  });
 });
 
 test.describe('Admin User Management - Pagination', () => {