feat: add knowledge markdown formatting and detail retrieval

- Implemented KnowledgeWebsiteMarkdownPrompt for formatting webpage content into Markdown.
- Added GetItemDetail method in KnowledgeHandler to retrieve knowledge item details.
- Introduced KnowledgeDetailDrawer component for displaying knowledge item details in the admin web interface.
- Created MarkdownPreview component for rendering Markdown content.
- Added knowledge chunking and URL parsing logic to handle webpage content extraction and formatting.
- Updated database schema to include markdown_content in knowledge_items table.

apps/admin-web/src/lib/api.ts

@@ -21,6 +21,7 @@ import type {
   KnowledgeGroup,
   KnowledgeGroupRequest,
   KnowledgeItem,
+  KnowledgeItemDetail,
   KnowledgeTextItemRequest,
   KnowledgeURLItemRequest,
   Keyword,
@@ -248,6 +249,9 @@ export const knowledgeApi = {
       params: groupId ? { group_id: groupId } : undefined,
     });
   },
+  detail(id: number) {
+    return apiClient.get<KnowledgeItemDetail>(`/api/tenant/knowledge/items/${id}`);
+  },
   createTextItem(payload: KnowledgeTextItemRequest) {
     return apiClient.post<KnowledgeItem, KnowledgeTextItemRequest>(
       "/api/tenant/knowledge/items/text",