feat: resolve and display article titles for naddr references

- Add articleTitleResolver service to fetch article titles from relays
- Extract naddr identifiers from markdown content
- Fetch article titles in parallel using relay pool
- Replace naddr references with actual article titles
- Fallback to identifier if title fetch fails
- Update markdown processing to be async for title resolution
- Pass relayPool through component tree to enable resolution

Example: nostr:naddr1... now shows as "My Article Title" instead of "article:identifier"

Improves readability by showing human-friendly article titles in cross-references

src/components/ContentPanel.tsx

@@ -3,6 +3,7 @@ import ReactMarkdown from 'react-markdown'
 import remarkGfm from 'remark-gfm'
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
 import { faSpinner } from '@fortawesome/free-solid-svg-icons'
+import { RelayPool } from 'applesauce-relay'
 import { Highlight } from '../types/highlights'
 import { readingTime } from 'reading-time-estimator'
 import { hexToRgb } from '../utils/colorHelpers'
@@ -32,6 +33,7 @@ interface ContentPanelProps {
   currentUserPubkey?: string
   followedPubkeys?: Set<string>
   settings?: UserSettings
+  relayPool?: RelayPool | null
   // For highlight creation
   onTextSelection?: (text: string) => void
   onClearSelection?: () => void
@@ -51,6 +53,7 @@ const ContentPanel: React.FC<ContentPanelProps> = ({
   highlightStyle = 'marker',
   highlightColor = '#ffff00',
   settings,
+  relayPool,
   onHighlightClick,
   selectedHighlightId,
   highlightVisibility = { nostrverse: true, friends: true, mine: true },
@@ -59,7 +62,7 @@ const ContentPanel: React.FC<ContentPanelProps> = ({
   onTextSelection,
   onClearSelection
 }) => {
-  const { renderedHtml: renderedMarkdownHtml, previewRef: markdownPreviewRef, processedMarkdown } = useMarkdownToHTML(markdown)
+  const { renderedHtml: renderedMarkdownHtml, previewRef: markdownPreviewRef, processedMarkdown } = useMarkdownToHTML(markdown, relayPool)
   
   const { finalHtml, relevantHighlights } = useHighlightedContent({
     html,

src/components/ThreePaneLayout.tsx

@@ -302,6 +302,7 @@ const ThreePaneLayout: React.FC<ThreePaneLayoutProps> = (props) => {
               currentUserPubkey={props.currentUserPubkey}
               followedPubkeys={props.followedPubkeys}
               settings={props.settings}
+              relayPool={props.relayPool}
             />
           )}
         </div>