feat: Add end-to-end tests for DNS Provider Types and UI interactions

- Implement API tests for DNS Provider Types, validating built-in and custom providers.
- Create UI tests for provider selection, ensuring all types are displayed and descriptions are shown.
- Introduce fixtures for consistent test data across DNS Provider tests.
- Update manual DNS provider tests to improve structure and accessibility checks.

frontend/src/components/DNSProviderForm.tsx

@@ -187,7 +187,7 @@ export default function DNSProviderForm({
               onValueChange={setProviderType}
               disabled={!!provider} // Can't change type when editing
             >
-              <SelectTrigger id="provider-type">
+              <SelectTrigger id="provider-type" aria-label={t('dnsProviders.providerType')}>
                 <SelectValue placeholder={t('dnsProviders.selectProviderType')} />
               </SelectTrigger>
               <SelectContent>
@@ -208,11 +208,13 @@ export default function DNSProviderForm({
 
           {/* Provider Name */}
           <Input
+            id="provider-name"
             label={t('dnsProviders.providerName')}
             value={name}
             onChange={(e) => setName(e.target.value)}
             placeholder={t('dnsProviders.providerNamePlaceholder')}
             required
+            aria-label={t('dnsProviders.providerName')}
           />
 
           {/* Dynamic Credential Fields */}