feat(document retrieval): Authenticate Azure Document Intelligence using AzureDefaultCredential if API key is not provided

src/lib/components/admin/Settings/Documents.svelte

@@ -185,10 +185,9 @@
 
 		if (
 			RAGConfig.CONTENT_EXTRACTION_ENGINE === 'document_intelligence' &&
-			(RAGConfig.DOCUMENT_INTELLIGENCE_ENDPOINT === '' ||
-				RAGConfig.DOCUMENT_INTELLIGENCE_KEY === '')
+			RAGConfig.DOCUMENT_INTELLIGENCE_ENDPOINT === ''
 		) {
-			toast.error($i18n.t('Document Intelligence endpoint and key required.'));
+			toast.error($i18n.t('Document Intelligence endpoint required.'));
 			return;
 		}
 		if (
@@ -644,6 +643,7 @@
 								<SensitiveInput
 									placeholder={$i18n.t('Enter Document Intelligence Key')}
 									bind:value={RAGConfig.DOCUMENT_INTELLIGENCE_KEY}
+									required={false}
 								/>
 							</div>
 						{:else if RAGConfig.CONTENT_EXTRACTION_ENGINE === 'mistral_ocr'}