feat: add ManualDNSChallenge component and related hooks for manual DNS challenge management

- Implemented `useManualChallenge`, `useChallengePoll`, and `useManualChallengeMutations` hooks for managing manual DNS challenges.
- Created tests for the `useManualChallenge` hooks to ensure correct fetching and mutation behavior.
- Added `ManualDNSChallenge` component for displaying challenge details and actions.
- Developed end-to-end tests for the Manual DNS Provider feature, covering provider selection, challenge UI, and accessibility compliance.
- Included error handling tests for verification failures and network errors.

frontend/src/api/dnsProviders.ts

@@ -12,6 +12,11 @@ export type DNSProviderType =
   | 'hetzner'
   | 'vultr'
   | 'dnsimple'
+  // Custom plugin types
+  | 'manual'
+  | 'webhook'
+  | 'rfc2136'
+  | 'script'
 
 /** Represents a configured DNS provider */
 export interface DNSProvider {