Add long-form article reader (Phase 1 #1, NIP-23)

- fetchArticle(naddr): fetches kind 30023 by d-tag + author pubkey
- fetchAuthorArticles(pubkey): for future profile articles tab
- ArticleView: cover image, title, italic summary, author row (avatar +
  name + date), tag pills, full markdown body (DOMPurify sanitized),
  zap author button in header and footer, copy nostr: link, njump.me
  fallback on fetch error
- prose-article CSS: reader-optimised typography (15px base, 1.8 line
  height, h2 border, styled blockquote/code/pre/links/images)
- NoteContent: naddr1 clicks for kind 30023 now open ArticleView
  instead of falling through to njump.me
- openArticle(naddr) added to UI store with previousView tracking

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/nostr/client.ts

@@ -365,6 +365,36 @@ export async function decryptDM(event: NDKEvent, myPubkey: string): Promise<stri
   return instance.signer.decrypt(otherUser, event.content, "nip04");
 }
 
+export async function fetchArticle(naddr: string): Promise<NDKEvent | null> {
+  const instance = getNDK();
+  try {
+    const decoded = nip19.decode(naddr);
+    if (decoded.type !== "naddr") return null;
+    const { identifier, pubkey, kind } = decoded.data;
+    const filter: NDKFilter = {
+      kinds: [kind as NDKKind],
+      authors: [pubkey],
+      "#d": [identifier],
+      limit: 1,
+    };
+    const events = await instance.fetchEvents(filter, {
+      cacheUsage: NDKSubscriptionCacheUsage.ONLY_RELAY,
+    });
+    return Array.from(events)[0] ?? null;
+  } catch {
+    return null;
+  }
+}
+
+export async function fetchAuthorArticles(pubkey: string, limit = 20): Promise<NDKEvent[]> {
+  const instance = getNDK();
+  const filter: NDKFilter = { kinds: [NDKKind.Article], authors: [pubkey], limit };
+  const events = await instance.fetchEvents(filter, {
+    cacheUsage: NDKSubscriptionCacheUsage.ONLY_RELAY,
+  });
+  return Array.from(events).sort((a, b) => (b.created_at ?? 0) - (a.created_at ?? 0));
+}
+
 export async function fetchZapsReceived(pubkey: string, limit = 50): Promise<NDKEvent[]> {
   const instance = getNDK();
   const filter: NDKFilter = { kinds: [NDKKind.Zap], "#p": [pubkey], limit };

src/lib/nostr/index.ts

@@ -1 +1 @@
-export { getNDK, connectToRelays, fetchGlobalFeed, fetchFollowFeed, fetchReplies, publishNote, publishArticle, publishProfile, publishReaction, publishRepost, publishQuote, publishReply, publishContactList, fetchReactionCount, fetchUserNotes, fetchProfile, fetchZapsReceived, fetchZapsSent, fetchDMConversations, fetchDMThread, sendDM, decryptDM, fetchMuteList, publishMuteList, getStoredRelayUrls, addRelay, removeRelay, searchNotes, searchUsers } from "./client";
+export { getNDK, connectToRelays, fetchGlobalFeed, fetchFollowFeed, fetchReplies, publishNote, publishArticle, publishProfile, publishReaction, publishRepost, publishQuote, publishReply, publishContactList, fetchReactionCount, fetchUserNotes, fetchProfile, fetchArticle, fetchAuthorArticles, fetchZapsReceived, fetchZapsSent, fetchDMConversations, fetchDMThread, sendDM, decryptDM, fetchMuteList, publishMuteList, getStoredRelayUrls, addRelay, removeRelay, searchNotes, searchUsers } from "./client";