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.

packages/shared-types/src/index.ts

@@ -556,6 +556,10 @@ export interface KnowledgeItem {
   updated_at: string;
 }
 
+export interface KnowledgeItemDetail extends KnowledgeItem {
+  markdown_content: string | null;
+}
+
 export interface KnowledgeTextItemRequest {
   group_id: number;
   name: string;