refactor: extract components and utilities to keep files under 210 lines

- Extract types to src/types/bookmarks.ts
- Extract utility functions to src/utils/bookmarkUtils.tsx
- Extract BookmarkItem component to src/components/BookmarkItem.tsx
- Extract BookmarkList component to src/components/BookmarkList.tsx
- Extract bookmark fetching logic to src/services/bookmarkService.ts
- Reduce main Bookmarks component from 416 to 100 lines
- Maintain all functionality while improving code organization
- Pass all linting and type checking

src/utils/bookmarkUtils.tsx

@@ -0,0 +1,67 @@
+import React from 'react'
+import { ParsedContent, ParsedNode } from '../types/bookmarks'
+
+export const formatDate = (timestamp: number) => {
+  return new Date(timestamp * 1000).toLocaleDateString()
+}
+
+// Component to render parsed content using applesauce-content
+export const renderParsedContent = (parsedContent: ParsedContent) => {
+  if (!parsedContent || !parsedContent.children) {
+    return null
+  }
+
+  const renderNode = (node: ParsedNode, index: number): React.ReactNode => {
+    if (node.type === 'text') {
+      return <span key={index}>{node.value}</span>
+    }
+    
+    if (node.type === 'mention') {
+      return (
+        <a 
+          key={index}
+          href={`nostr:${node.encoded}`}
+          className="nostr-mention"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          {node.encoded}
+        </a>
+      )
+    }
+    
+    if (node.type === 'link') {
+      return (
+        <a 
+          key={index}
+          href={node.url}
+          className="nostr-link"
+          target="_blank"
+          rel="noopener noreferrer"
+        >
+          {node.url}
+        </a>
+      )
+    }
+    
+    if (node.children) {
+      return (
+        <span key={index}>
+          {node.children.map((child: ParsedNode, childIndex: number) => 
+            renderNode(child, childIndex)
+          )}
+        </span>
+      )
+    }
+    
+    return null
+  }
+
+  return (
+    <div className="parsed-content">
+      {parsedContent.children.map((node: ParsedNode, index: number) => 
+        renderNode(node, index)
+      )}
+    </div>
+  )
+}