Working feed: NDK + relay connection + live notes from Nostr

- Tailwind CSS + Zustand + NDK installed and configured
- Sidebar with feed/relays/settings navigation
- Global feed view with live notes from relays
- Profile fetching with caching and deduplication
- Relay connection with timeout handling
- Note cards with avatar, name, timestamp, content
- Dark theme, monospace, no-slop UI
- Devtools enabled for debugging

src/hooks/useProfile.ts

@@ -0,0 +1,35 @@
+import { useEffect, useState } from "react";
+import { fetchProfile } from "../lib/nostr";
+
+const profileCache = new Map<string, any>();
+const pendingRequests = new Map<string, Promise<any>>();
+
+export function useProfile(pubkey: string) {
+  const [profile, setProfile] = useState<any>(profileCache.get(pubkey) ?? null);
+
+  useEffect(() => {
+    if (profileCache.has(pubkey)) {
+      setProfile(profileCache.get(pubkey));
+      return;
+    }
+
+    // Deduplicate requests for the same pubkey
+    if (!pendingRequests.has(pubkey)) {
+      const request = fetchProfile(pubkey).then((p) => {
+        profileCache.set(pubkey, p ?? null);
+        pendingRequests.delete(pubkey);
+        return p;
+      }).catch(() => {
+        pendingRequests.delete(pubkey);
+        return null;
+      });
+      pendingRequests.set(pubkey, request);
+    }
+
+    pendingRequests.get(pubkey)!.then((p) => {
+      setProfile(p ?? null);
+    });
+  }, [pubkey]);
+
+  return profile;
+}