fix: enhance notifications and validation features

- Added URL validation for notification providers to ensure only valid http/https URLs are accepted.
- Implemented tests for URL validation scenarios in the Notifications component.
- Updated translations for error messages related to invalid URLs in multiple languages.
- Introduced new hooks for managing security headers and access lists in tests.
- Enhanced the ProviderForm component to reset state correctly when switching between add and edit modes.
- Improved user feedback with update indicators after saving changes to notification providers.
- Added mock implementations for new hooks in various test files to ensure consistent testing behavior.

frontend/src/components/__tests__/ProxyHostForm-dns.test.tsx

@@ -51,7 +51,15 @@ vi.mock('../../hooks/useSecurity', () => ({
 
 vi.mock('../../hooks/useSecurityHeaders', () => ({
   useSecurityHeaderProfiles: vi.fn(() => ({
-    profiles: [],
+    data: [],
+    isLoading: false,
+    error: null,
+  })),
+}))
+
+vi.mock('../../hooks/useAccessLists', () => ({
+  useAccessLists: vi.fn(() => ({
+    data: [],
     isLoading: false,
     error: null,
   })),

frontend/src/components/__tests__/ProxyHostForm-uptime.test.tsx

@@ -31,6 +31,27 @@ vi.mock('../../hooks/useCertificates', () => ({
   useCertificates: vi.fn(() => ({ certificates: [], isLoading: false, error: null })),
 }))
 
+vi.mock('../../hooks/useSecurityHeaders', () => ({
+  useSecurityHeaderProfiles: vi.fn(() => ({ data: [], isLoading: false, error: null })),
+}))
+
+vi.mock('../../hooks/useAccessLists', () => ({
+  useAccessLists: vi.fn(() => ({
+    data: [],
+    isLoading: false,
+    error: null,
+  })),
+}))
+
+vi.mock('../../hooks/useDNSDetection', () => ({
+  useDetectDNSProvider: vi.fn(() => ({
+    mutateAsync: vi.fn(),
+    isPending: false,
+    data: undefined,
+    reset: vi.fn(),
+  })),
+}))
+
 // stub global fetch for health endpoint
 vi.stubGlobal('fetch', vi.fn(() => Promise.resolve({ json: () => Promise.resolve({ internal_ip: '127.0.0.1' }) })))
 

frontend/src/components/__tests__/SecurityNotificationSettingsModal.test.tsx

@@ -154,11 +154,10 @@ describe('SecurityNotificationSettingsModal', () => {
     renderModal();
 
     await waitFor(() => {
-      expect(screen.getByLabelText('Enable Notifications')).toBeTruthy();
+      expect(screen.getByLabelText('Enable Notifications')).toBeChecked();
     });
 
     const enableSwitch = screen.getByLabelText('Enable Notifications') as HTMLInputElement;
-    expect(enableSwitch.checked).toBe(true);
 
     // Disable notifications
     await user.click(enableSwitch);